1
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Huang H, Chang S, Cui T, Huang M, Qu J, Zhang H, Lu T, Zhang X, Zhou C, Feng Y. An inhibitory mechanism of AasS, an exogenous fatty acid scavenger: Implications for re-sensitization of FAS II antimicrobials. PLoS Pathog 2024; 20:e1012376. [PMID: 39008531 PMCID: PMC11271967 DOI: 10.1371/journal.ppat.1012376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 07/25/2024] [Accepted: 06/26/2024] [Indexed: 07/17/2024] Open
Abstract
Antimicrobial resistance is an ongoing "one health" challenge of global concern. The acyl-ACP synthetase (termed AasS) of the zoonotic pathogen Vibrio harveyi recycles exogenous fatty acid (eFA), bypassing the requirement of type II fatty acid synthesis (FAS II), a druggable pathway. A growing body of bacterial AasS-type isoenzymes compromises the clinical efficacy of FAS II-directed antimicrobials, like cerulenin. Very recently, an acyl adenylate mimic, C10-AMS, was proposed as a lead compound against AasS activity. However, the underlying mechanism remains poorly understood. Here we present two high-resolution cryo-EM structures of AasS liganded with C10-AMS inhibitor (2.33 Å) and C10-AMP intermediate (2.19 Å) in addition to its apo form (2.53 Å). Apart from our measurements for C10-AMS' Ki value of around 0.6 μM, structural and functional analyses explained how this inhibitor interacts with AasS enzyme. Unlike an open state of AasS, ready for C10-AMP formation, a closed conformation is trapped by the C10-AMS inhibitor. Tight binding of C10-AMS blocks fatty acyl substrate entry, and therefore inhibits AasS action. Additionally, this intermediate analog C10-AMS appears to be a mixed-type AasS inhibitor. In summary, our results provide the proof of principle that inhibiting salvage of eFA by AasS reverses the FAS II bypass. This facilitates the development of next-generation anti-bacterial therapeutics, esp. the dual therapy consisting of C10-AMS scaffold derivatives combined with certain FAS II inhibitors.
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Affiliation(s)
- Haomin Huang
- Key Laboratory of Multiple Organ Failure, Ministry of Education; Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shenghai Chang
- Center of Cryo-Electron Microscopy, Zhejiang University, Hangzhou, Zhejiang, China
| | - Tao Cui
- School of Life Sciences, Northwestern Polytechnical University, Xi’an, Shaanxi, China
| | - Man Huang
- Key Laboratory of Multiple Organ Failure, Ministry of Education; Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jiuxin Qu
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Huimin Zhang
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Ting Lu
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Xing Zhang
- Center of Cryo-Electron Microscopy, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chun Zhou
- School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Youjun Feng
- Key Laboratory of Multiple Organ Failure, Ministry of Education; Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Department of Clinical Laboratory, Shenzhen Third People’s Hospital, National Clinical Research Center for Infectious Diseases, The Second Affiliated Hospital of Southern University of Science and Technology, Shenzhen, Guangdong, China
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2
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Rutherford J, Avad K, Dureja C, Norseeda K, GC B, Wu C, Sun D, Hevener KE, Hurdle JG. Evaluation of Fusobacterium nucleatum Enoyl-ACP Reductase (FabK) as a Narrow-Spectrum Drug Target. ACS Infect Dis 2024; 10:1612-1623. [PMID: 38597503 PMCID: PMC11091888 DOI: 10.1021/acsinfecdis.3c00710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 04/11/2024]
Abstract
Fusobacterium nucleatum, a pathobiont inhabiting the oral cavity, contributes to opportunistic diseases, such as periodontal diseases and gastrointestinal cancers, which involve microbiota imbalance. Broad-spectrum antimicrobial agents, while effective against F. nucleatum infections, can exacerbate dysbiosis. This necessitates the discovery of more targeted narrow-spectrum antimicrobial agents. We therefore investigated the potential for the fusobacterial enoyl-ACP reductase II (ENR II) isoenzyme FnFabK (C4N14_ 04250) as a narrow-spectrum drug target. ENRs catalyze the rate-limiting step in the bacterial fatty acid synthesis pathway. Bioinformatics revealed that of the four distinct bacterial ENR isoforms, F. nucleatum specifically encodes FnFabK. Genetic studies revealed that fabK was indispensable for F. nucleatum growth, as the gene could not be deleted, and silencing of its mRNA inhibited growth under the test conditions. Remarkably, exogenous fatty acids failed to rescue growth inhibition caused by the silencing of fabK. Screening of synthetic phenylimidazole analogues of a known FabK inhibitor identified an inhibitor (i.e., 681) of FnFabK enzymatic activity and F. nucleatum growth, with an IC50 of 2.1 μM (1.0 μg/mL) and a MIC of 0.4 μg/mL, respectively. Exogenous fatty acids did not attenuate the activity of 681 against F. nucleatum. Furthermore, FnFabK was confirmed as the intracellular target of 681 based on the overexpression of FnFabK shifting MICs and 681-resistant mutants having amino acid substitutions in FnFabK or mutations in other genetic loci affecting fatty acid biosynthesis. 681 had minimal activity against a range of commensal flora, and it was less active against streptococci in physiologic fatty acids. Taken together, FnFabK is an essential enzyme that is amenable to drug targeting for the discovery and development of narrow-spectrum antimicrobial agents.
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Affiliation(s)
- Jacob
T. Rutherford
- Center
for Infectious and Inflammatory Diseases, Institute of Biosciences
and Technology, Department of Translational Medical Sciences, Texas A&M Health Science Center, Houston, Texas 77030, United States
| | - Kristiana Avad
- Department
of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
| | - Chetna Dureja
- Center
for Infectious and Inflammatory Diseases, Institute of Biosciences
and Technology, Department of Translational Medical Sciences, Texas A&M Health Science Center, Houston, Texas 77030, United States
| | - Krissada Norseeda
- Department
of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, Hawaii 96720, United States
| | - Bibek GC
- Department
of Microbiology & Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030, United States
| | - Chenggang Wu
- Department
of Microbiology & Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, Texas 77030, United States
| | - Dianqing Sun
- Department
of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, Hawaii 96720, United States
| | - Kirk E. Hevener
- Department
of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee 38163, United States
| | - Julian G. Hurdle
- Center
for Infectious and Inflammatory Diseases, Institute of Biosciences
and Technology, Department of Translational Medical Sciences, Texas A&M Health Science Center, Houston, Texas 77030, United States
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3
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Wongdontree P, Millan-Oropeza A, Upfold J, Lavergne JP, Halpern D, Lambert C, Page A, Kénanian G, Grangeasse C, Henry C, Fouet A, Gloux K, Anba-Mondoloni J, Gruss A. Oxidative stress is intrinsic to staphylococcal adaptation to fatty acid synthesis antibiotics. iScience 2024; 27:109505. [PMID: 38577105 PMCID: PMC10993138 DOI: 10.1016/j.isci.2024.109505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 12/08/2023] [Accepted: 03/13/2024] [Indexed: 04/06/2024] Open
Abstract
Antibiotics inhibiting the fatty acid synthesis pathway (FASII) of the major pathogen Staphylococcus aureus reach their enzyme targets, but bacteria continue growth by using environmental fatty acids (eFAs) to produce phospholipids. We assessed the consequences and effectors of FASII-antibiotic (anti-FASII) adaptation. Anti-FASII induced lasting expression changes without genomic rearrangements. Several identified regulators affected the timing of adaptation outgrowth. Adaptation resulted in decreased expression of major virulence factors. Conversely, stress responses were globally increased and adapted bacteria were more resistant to peroxide killing. Importantly, pre-exposure to peroxide led to faster anti-FASII-adaptation by stimulating eFA incorporation. This adaptation differs from reports of peroxide-stimulated antibiotic efflux, which leads to tolerance. In vivo, anti-FASII-adapted S. aureus killed the insect host more slowly but continued multiplying. We conclude that staphylococcal adaptation to FASII antibiotics involves reprogramming, which decreases virulence and increases stress resistance. Peroxide, produced by the host to combat infection, favors anti-FASII adaptation.
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Affiliation(s)
- Paprapach Wongdontree
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Aaron Millan-Oropeza
- PAPPSO Platform, Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Jennifer Upfold
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Jean-Pierre Lavergne
- Bacterial Pathogens and Protein Phosphorylation, Molecular Microbiology and Structural Biology, UMR 5086 - CNRS / Université de Lyon, Building IBCP, 7 Passage du Vercors, Lyon, France
| | - David Halpern
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Clara Lambert
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Adeline Page
- Protein Science Facility, SFR BioSciences, CNRS, UMS3444, INSERM US8, Université de Lyon, Lyon, France
| | - Gérald Kénanian
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Christophe Grangeasse
- Bacterial Pathogens and Protein Phosphorylation, Molecular Microbiology and Structural Biology, UMR 5086 - CNRS / Université de Lyon, Building IBCP, 7 Passage du Vercors, Lyon, France
| | - Céline Henry
- PAPPSO Platform, Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Agnès Fouet
- Université Paris Cité, Institut Cochin, INSERM, U1016, CNRS, UMR8104, Paris, France
| | - Karine Gloux
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Jamila Anba-Mondoloni
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
| | - Alexandra Gruss
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350 Jouy-en-Josas, France
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4
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Myers MJ, Xu Z, Ryan BJ, DeMars ZR, Ridder MJ, Johnson DK, Krute CN, Flynn TS, Kashipathy MM, Battaile KP, Schnicker N, Lovell S, Freudenthal BD, Bose JL. Molecular basis for the activation of the Fatty Acid Kinase complex of Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.19.585040. [PMID: 38562735 PMCID: PMC10983944 DOI: 10.1101/2024.03.19.585040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Gram-positive bacteria utilize a Fatty Acid Kinase (FAK) complex to harvest fatty acids from the environment. The complex, consisting of the fatty acid kinase, FakA, and an acyl carrier protein, FakB, is known to impact virulence and disease outcomes. However, FAK's structure and enzymatic mechanism remain poorly understood. Here, we used a combination of modeling, biochemical, and cell-based approaches to establish critical details of FAK activity. Solved structures of the apo and ligand-bound FakA kinase domain captured the protein state through ATP hydrolysis. Additionally, targeted mutagenesis of an understudied FakA Middle domain identified critical residues within a metal-binding pocket that contribute to FakA dimer stability and protein function. Regarding the complex, we demonstrated nanomolar affinity between FakA and FakB and generated computational models of the complex's quaternary structure. Together, these data provide critical insight into the structure and function of the FAK complex which is essential for understanding its mechanism.
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5
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Lee TH, Charchar P, Separovic F, Reid GE, Yarovsky I, Aguilar MI. The intricate link between membrane lipid structure and composition and membrane structural properties in bacterial membranes. Chem Sci 2024; 15:3408-3427. [PMID: 38455013 PMCID: PMC10915831 DOI: 10.1039/d3sc04523d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 01/26/2024] [Indexed: 03/09/2024] Open
Abstract
It is now evident that the cell manipulates lipid composition to regulate different processes such as membrane protein insertion, assembly and function. Moreover, changes in membrane structure and properties, lipid homeostasis during growth and differentiation with associated changes in cell size and shape, and responses to external stress have been related to drug resistance across mammalian species and a range of microorganisms. While it is well known that the biomembrane is a fluid self-assembled nanostructure, the link between the lipid components and the structural properties of the lipid bilayer are not well understood. This perspective aims to address this topic with a view to a more detailed understanding of the factors that regulate bilayer structure and flexibility. We describe a selection of recent studies that address the dynamic nature of bacterial lipid diversity and membrane properties in response to stress conditions. This emerging area has important implications for a broad range of cellular processes and may open new avenues of drug design for selective cell targeting.
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Affiliation(s)
- Tzong-Hsien Lee
- Department of Biochemistry and Molecular Biology, Monash University Clayton VIC 3800 Australia
| | - Patrick Charchar
- School of Engineering, RMIT University Melbourne Victoria 3001 Australia
| | - Frances Separovic
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne VIC 3010 Australia
| | - Gavin E Reid
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne VIC 3010 Australia
- Department of Biochemistry and Pharmacology, University of Melbourne Parkville VIC 3010 Australia
| | - Irene Yarovsky
- School of Engineering, RMIT University Melbourne Victoria 3001 Australia
| | - Marie-Isabel Aguilar
- Department of Biochemistry and Molecular Biology, Monash University Clayton VIC 3800 Australia
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6
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Dureja C, Rutherford JT, Pavel FB, Norseeda K, Prah I, Sun D, Hevener KE, Hurdle JG. In vivo evaluation of Clostridioides difficile enoyl-ACP reductase II (FabK) inhibition by phenylimidazole unveils a promising narrow-spectrum antimicrobial strategy. Antimicrob Agents Chemother 2024; 68:e0122223. [PMID: 38265216 PMCID: PMC10916379 DOI: 10.1128/aac.01222-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 12/18/2023] [Indexed: 01/25/2024] Open
Abstract
Clostridioides difficile infection (CDI) is a leading cause of hospital-acquired diarrhea, which often stems from disruption of the gut microbiota by broad-spectrum antibiotics. The increasing prevalence of antibiotic-resistant C. difficile strains, combined with disappointing clinical trial results for recent antibiotic candidates, underscores the urgent need for novel CDI antibiotics. To this end, we investigated C. difficile enoyl ACP reductase (CdFabK), a crucial enzyme in de novo fatty acid synthesis, as a drug target for microbiome-sparing antibiotics. To test this concept, we evaluated the efficacy and in vivo spectrum of activity of the phenylimidazole analog 296, which is validated to inhibit intracellular CdFabK. Against major CDI-associated ribotypes 296 had an Minimum inhibitory concentration (MIC90) of 2 µg/mL, which was comparable to vancomycin (1 µg/mL), a standard of care antibiotic. In addition, 296 achieved high colonic concentrations and displayed dosed-dependent efficacy in mice with colitis CDI. Mice that were given 296 retained colonization resistance to C. difficile and had microbiomes that resembled the untreated mice. Conversely, both vancomycin and fidaxomicin induced significant changes to mice microbiomes, in a manner consistent with prior reports. CdFabK, therefore, represents a potential target for microbiome-sparing CDI antibiotics, with phenylimidazoles providing a good chemical starting point for designing such agents.
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Affiliation(s)
- Chetna Dureja
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Jacob T. Rutherford
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Fahad B.A. Pavel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Krissada Norseeda
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, Hawaii, USA
| | - Isaac Prah
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
| | - Dianqing Sun
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, Hawaii, USA
| | - Kirk E. Hevener
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Julian G. Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, USA
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7
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Sears A, Hentz F, de Souza J, Wenner B, Ward RE, Batistel F. Supply of palmitic, stearic, and oleic acid changes rumen fiber digestibility and microbial composition. J Dairy Sci 2024; 107:902-916. [PMID: 37776997 DOI: 10.3168/jds.2023-23568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 09/10/2023] [Indexed: 10/02/2023]
Abstract
The concept that fat supplementation impairs total-tract fiber digestibility in ruminants has been widely accepted over the past decades. Nevertheless, the recent interest in the dietary fatty acid profile to dairy cows enlightened the possible beneficial effect of specific fatty acids (e.g., palmitic, stearic, and oleic acids) on total-tract fiber digestibility. Because palmitic, stearic, and oleic acids are the main fatty acids present in ruminal bacterial cells, we hypothesize that the dietary supply of these fatty acids will favor their incorporation into the bacterial cell membranes, which will support the growth and enrichment of fiber-digesting bacteria in the rumen. Our objective in this experiment was to investigate how dietary supply of palmitic, stearic, and oleic acid affect fiber digestion, bacterial membrane fatty acid profile, microbial growth, and composition of the rumen bacterial community. Diets were randomly assigned to 8 single-flow continuous culture fermenters arranged in a replicated 4 × 4 Latin square with four 11-d experimental periods. Treatments were (1) a control basal diet without supplemental fatty acids (CON); (2) the control diet plus palmitic acid (PA); (3) the control diet plus stearic acid (SA); and (4) the control diet plus oleic acid (OA). All fatty acid treatments were included in the diet at 1.5% of the diet (dry matter [DM] basis). The basal diet contained 50% orchardgrass hay and 50% concentrate (DM basis) and was supplied at a rate of 60 g of DM/d in 2 equal daily offers (0800 and 1600 h). Data were analyzed using a mixed model considering treatments as fixed effect and period and fermenter as random effects. Our results indicate that PA increased in vitro fiber digestibility by 6 percentage units compared with the CON, while SA had no effect and OA decreased fiber digestibility by 8 percentage units. Oleic acid decreased protein expression of the enzymes acetyl-CoA carboxylase compared with CON and PA, while fatty acid synthase was reduced by PA, SA, and OA. We observed that PA, but not SA or OA, altered the bacterial community composition by enhancing bacterial groups responsible for fiber digestion. Although the dietary fatty acids did not affect the total lipid content and the phospholipid fraction in the bacterial cell, PA increased the flow of anteiso C13:0 and anteiso C15:0 in the phospholipidic membrane compared to the other treatments. In addition, OA increased the flow of C18:1 cis-9 and decreased C18:2 cis-9,cis-12 in the bacterial phospholipidic membranes compared to the other treatments. Palmitic acid tended to increase bacterial growth compared to other treatments, whereas SA and OA did not affect bacterial growth compared with CON. To our knowledge, this is the first research providing evidence that palmitic acid supports ruminal fiber digestion through shifts in bacterial fatty acid metabolism that result in changes in growth and abundance of fiber-degrading bacteria in the microbial community.
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Affiliation(s)
- Austin Sears
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 53706
| | - Fernanda Hentz
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | | | - Benjamin Wenner
- Department of Animal Sciences, The Ohio State University, Columbus, OH 43210
| | - Robert E Ward
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, Logan, UT 43210
| | - Fernanda Batistel
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611.
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8
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Gwynne PJ, Stocks KLK, Karozichian ES, Pandit A, Hu LT. Metabolic modeling predicts unique drug targets in Borrelia burgdorferi. mSystems 2023; 8:e0083523. [PMID: 37855615 PMCID: PMC10734484 DOI: 10.1128/msystems.00835-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 08/22/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE Lyme disease is often treated using long courses of antibiotics, which can cause side effects for patients and risks the evolution of antimicrobial resistance. Narrow-spectrum antimicrobials would reduce these risks, but their development has been slow because the Lyme disease bacterium, Borrelia burgdorferi, is difficult to work with in the laboratory. To accelerate the drug discovery pipeline, we developed a computational model of B. burgdorferi's metabolism and used it to predict essential enzymatic reactions whose inhibition prevented growth in silico. These predictions were validated using small-molecule enzyme inhibitors, several of which were shown to have specific activity against B. burgdorferi. Although the specific compounds used are not suitable for clinical use, we aim to use them as lead compounds to develop optimized drugs targeting the pathways discovered here.
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Affiliation(s)
- Peter J. Gwynne
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Kee-Lee K. Stocks
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Elysse S. Karozichian
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Aarya Pandit
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
| | - Linden T. Hu
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts Lyme Disease Initiative, Tufts University, Boston, Massachusetts, USA
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9
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Pruitt EL, Zhang R, Ross DH, Ashford NK, Chen X, Alonzo F, Bush MF, Werth BJ, Xu L. Elucidating the impact of bacterial lipases, human serum albumin, and FASII inhibition on the utilization of exogenous fatty acids by Staphylococcus aureus. mSphere 2023; 8:e0036823. [PMID: 38014966 PMCID: PMC10732024 DOI: 10.1128/msphere.00368-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/26/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE Incorporation of host-derived exogenous fatty acids (eFAs), particularly unsaturated fatty acids (UFAs), by Staphylococcus aureus could affect the bacterial membrane fluidity and susceptibility to antimicrobials. In this work, we found that glycerol ester hydrolase (Geh) is the primary lipase hydrolyzing cholesteryl esters and, to a lesser extent, triglycerides and that human serum albumin (HSA) could serve as a buffer of eFAs, where low levels of HSA facilitate the utilization of eFAs but high levels of HSA inhibit it. The fact that the type II fatty acid synthesis (FASII) inhibitor, AFN-1252, leads to an increase in UFA content even in the absence of eFA suggests that membrane property modulation is part of its mechanism of action. Thus, Geh and/or the FASII system look to be promising targets to enhance S. aureus killing in a host environment by restricting eFA utilization or modulating membrane properties, respectively.
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Affiliation(s)
- Emily L. Pruitt
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Rutan Zhang
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | - Dylan H. Ross
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | | | - Xi Chen
- Department of Microbiology and Immunology, Loyola University Chicago-Stritch School of Medicine, Maywood, Illinois, USA
| | - Francis Alonzo
- Department of Microbiology and Immunology, Loyola University Chicago-Stritch School of Medicine, Maywood, Illinois, USA
| | - Matthew F. Bush
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Brian J. Werth
- Department of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Libin Xu
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
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10
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Ellermann M. Emerging mechanisms by which endocannabinoids and their derivatives modulate bacterial populations within the gut microbiome. ADVANCES IN DRUG AND ALCOHOL RESEARCH 2023; 3:11359. [PMID: 38389811 PMCID: PMC10880783 DOI: 10.3389/adar.2023.11359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 11/28/2023] [Indexed: 02/24/2024]
Abstract
Bioactive lipids such as endocannabinoids serve as important modulators of host health and disease through their effects on various host functions including central metabolism, gut physiology, and immunity. Furthermore, changes to the gut microbiome caused by external factors such as diet or by disease development have been associated with altered endocannabinoid tone and disease outcomes. These observations suggest the existence of reciprocal relationships between host lipid signaling networks and bacterial populations that reside within the gut. Indeed, endocannabinoids and their congeners such as N-acylethanolamides have been recently shown to alter bacterial growth, functions, physiology, and behaviors, therefore introducing putative mechanisms by which these bioactive lipids directly modulate the gut microbiome. Moreover, these potential interactions add another layer of complexity to the regulation of host health and disease pathogenesis that may be mediated by endocannabinoids and their derivatives. This mini review will summarize recent literature that exemplifies how N-acylethanolamides and monoacylglycerols including endocannabinoids can impact bacterial populations in vitro and within the gut microbiome. We also highlight exciting preclinical studies that have engineered gut bacteria to synthesize host N-acylethanolamides or their precursors as potential strategies to treat diseases that are in part driven by aberrant lipid signaling, including obesity and inflammatory bowel diseases.
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Affiliation(s)
- Melissa Ellermann
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States
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11
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Dureja C, Rutherford JT, Pavel FBA, Norseeda K, Prah I, Sun D, Hevener KE, Hurdle JG. In vivo evaluation of Clostridioides difficile enoyl-ACP reductase II (FabK) Inhibition by phenylimidazole unveils a promising narrow-spectrum antimicrobial strategy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.22.559005. [PMID: 37790427 PMCID: PMC10543012 DOI: 10.1101/2023.09.22.559005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Clostridioides difficile infection (CDI) is a leading cause of hospital-acquired diarrhea, which often stem from disruption of the gut microbiota by broad-spectrum antibiotics. The increasing prevalence of antibiotic-resistant C. difficile strains, combined with disappointing clinical trials results for recent antibiotic candidates, underscore the urgent need for novel CDI antibiotics. To this end, we investigated C. difficile enoyl ACP reductase (CdFabK), a crucial enzyme in de novo fatty acid synthesis, as a drug target for microbiome-sparing antibiotics. To test this concept, we evaluated the efficacy and in vivo spectrum of activity of the phenylimidazole analog 296, which is validated to inhibit intracellular CdFabK. Against major CDI-associated ribotypes 296 had an MIC90 of 2 μg/ml, which was comparable to vancomycin (1 μg/ml), a standard of care antibiotic. In addition, 296 achieved high colonic concentrations and displayed dosed-dependent efficacy in mice with colitis CDI. Mice that were given 296 retained colonization resistance to C. difficile and had microbiomes that resembled the untreated mice. Conversely, both vancomycin and fidaxomicin induced significant changes to mice microbiomes, in a manner consistent with prior reports. CdFabK therefore represents a potential target for microbiome-sparing CDI antibiotics, with phenylimidazoles providing a good chemical starting point for designing such agents.
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Affiliation(s)
- Chetna Dureja
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
| | - Jacob T. Rutherford
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
| | - Fahad B. A. Pavel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, Tennessee 38105, USA
| | - Krissada Norseeda
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, Hawaii 96720, USA
| | - Isaac Prah
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
| | - Dianqing Sun
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, 200 W. Kawili Street, Hilo, Hawaii 96720, USA
| | - Kirk E. Hevener
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, 881 Madison Avenue, Memphis, Tennessee 38105, USA
| | - Julian G. Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, 2121 West Holcombe Blvd., Houston, Texas 77030, USA
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12
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Kuiack RC, Tuffs SW, Dufresne K, Flick R, McCormick JK, McGavin MJ. The fadXDEBA locus of Staphylococcus aureus is required for metabolism of exogenous palmitic acid and in vivo growth. Mol Microbiol 2023; 120:425-438. [PMID: 37501506 DOI: 10.1111/mmi.15131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 07/05/2023] [Accepted: 07/10/2023] [Indexed: 07/29/2023]
Abstract
In Staphylococcus aureus, genes that should confer the capacity to metabolize fatty acids by β-oxidation occur in the fadXDEBA locus, but their function has not been elucidated. Previously, incorporation into phospholipid through the fatty acid kinase FakA pathway was thought to be the only option available for S. aureus to metabolize exogenous saturated fatty acids. We now find that in S. aureus USA300, a fadX::lux reporter was repressed by glucose and induced by palmitic acid but not stearic acid, while in USA300ΔfakA basal expression was significantly elevated, and enhanced in response to both fatty acids. When cultures were supplemented with palmitic acid, palmitoyl-CoA representing the first metabolite in the β-oxidation pathway was detected in USA300, but not in a fadXDEBA deletion mutant USA300Δfad, which relative to USA300 exhibited increased incorporation of palmitic acid into phospholipid accompanied by a rapid loss of viability. USA300Δfad also exhibited significantly reduced viability in a murine tissue abscess infection model. Our data are consistent with FakA-mediated incorporation of fatty acids into phospholipid as a preferred pathway for metabolism of exogenous fatty acids, while the fad locus is critical for metabolism of palmitic acid, which is the most abundant free fatty acid in human plasma.
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Affiliation(s)
- Robert C Kuiack
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Stephen W Tuffs
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Karine Dufresne
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Robert Flick
- Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - John K McCormick
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
- Lawson Health Research Institute, London, Ontario, Canada
- Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
| | - Martin J McGavin
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
- Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
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13
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Subramanian C, Yun MK, Frank MM, Rock CO. Lysophosphatidylglycerol (LPG) phospholipase D maintains membrane homeostasis in Staphylococcus aureus by converting LPG to lysophosphatidic acid. J Biol Chem 2023; 299:104863. [PMID: 37236358 PMCID: PMC10404611 DOI: 10.1016/j.jbc.2023.104863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 05/17/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Lysophospholipids are deacylated derivatives of their bilayer forming phospholipid counterparts that are present at low concentrations in cells. Phosphatidylglycerol (PG) is the principal membrane phospholipid in Staphylococcus aureus and lysophosphatidylglycerol (LPG) is detected in low abundance. Here, we used a mass spectrometry screen to identify locus SAUSA300_1020 as the gene responsible for maintaining low concentrations of 1-acyl-LPG in S. aureus. The SAUSA300_1020 gene encodes a protein with a predicted amino terminal transmembrane α-helix attached to a globular glycerophosphodiester phosphodiesterase (GDPD) domain. We determined that the purified protein lacking the hydrophobic helix (LpgDΔN) possesses cation-dependent lysophosphatidylglycerol phospholipase D activity that generates both lysophosphatidic acid (LPA) and cyclic-LPA products and hydrolyzes cyclic-LPA to LPA. Mn2+ was the highest affinity cation and stabilized LpgDΔN to thermal denaturation. LpgDΔN was not specific for the phospholipid headgroup and degraded 1-acyl-LPG, but not 2-acyl-LPG. Furthermore, a 2.1 Å crystal structure shows that LpgDΔN adopts the GDPD variation of the TIM barrel architecture except for the length and positioning of helix α6 and sheet β7. These alterations create a hydrophobic diffusion path for LPG to access the active site. The LpgD active site has the canonical GDPD metal binding and catalytic residues, and our biochemical characterization of site-directed mutants support a two-step mechanism involving a cyclic-LPA intermediate. Thus, the physiological function of LpgD in S. aureus is to convert LPG to LPA, which is re-cycled into the PG biosynthetic pathway at the LPA acyltransferase step to maintain membrane PG molecular species homeostasis.
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Affiliation(s)
- Chitra Subramanian
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Mi-Kyung Yun
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Matthew M Frank
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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14
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Pruitt EL, Zhang R, Ross DH, Ashford NK, Chen X, Alonzo F, Bush MF, Werth BJ, Xu L. Elucidating the Impact of Bacterial Lipases, Human Serum Albumin, and FASII Inhibition on the Utilization of Exogenous Fatty Acids by Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.29.547085. [PMID: 37425828 PMCID: PMC10327171 DOI: 10.1101/2023.06.29.547085] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Staphylococcus aureus only synthesizes straight-chain or branched-chain saturated fatty acids (SCFAs or BCFAs) via the type II fatty acid synthesis (FASII) pathway, but as a highly adaptive pathogen, S. aureus can also utilize host-derived exogenous fatty acids (eFAs), including SCFAs and unsaturated fatty acids (UFAs). S. aureus secretes three lipases, Geh, sal1, and SAUSA300_0641, which could perform the function of releasing fatty acids from host lipids. Once released, the FAs are phosphorylated by the fatty acid kinase, FakA, and incorporated into the bacterial lipids. In this study, we determined the substrate specificity of S. aureus secreted lipases, the effect of human serum albumin (HSA) on eFA incorporation, and the effect of FASII inhibitor, AFN-1252, on eFA incorporation using comprehensive lipidomics. When grown with major donors of fatty acids, cholesteryl esters (CEs) and triglycerides (TGs), Geh was found to be the primary lipase responsible for hydrolyzing CEs, but other lipases could compensate for the function of Geh in hydrolyzing TGs. Lipidomics showed that eFAs were incorporated into all major S. aureus lipid classes and that fatty acid-containing HSA can serve as a source of eFAs. Furthermore, S. aureus grown with UFAs displayed decreased membrane fluidity and increased production of reactive oxygen species (ROS). Exposure to AFN-1252 enhanced UFAs in the bacterial membrane, even without a source of eFAs, indicating a FASII pathway modification. Thus, the incorporation of eFAs alters the S. aureus lipidome, membrane fluidity, and ROS formation, which could affect host-pathogen interactions and susceptibility to membrane-targeting antimicrobials.
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Affiliation(s)
- Emily L. Pruitt
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Rutan Zhang
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | - Dylan H. Ross
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | | | - Xi Chen
- Department of Microbiology and Immunology, Loyola University Chicago-Stritch School of Medicine, Maywood, Illinois, USA
| | - Francis Alonzo
- Department of Microbiology and Immunology, Loyola University Chicago-Stritch School of Medicine, Maywood, Illinois, USA
| | - Matthew F. Bush
- Department of Chemistry, University of Washington, Seattle, Washington, USA
| | - Brian J. Werth
- Department of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Libin Xu
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
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15
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Norseeda K, Bin Aziz Pavel F, Rutherford JT, Meer HN, Dureja C, Hurdle JG, Hevener KE, Sun D. Synthesis and evaluation of phenylimidazole FabK inhibitors as new Anti-C. Difficile agents. Bioorg Med Chem 2023; 88-89:117330. [PMID: 37224699 PMCID: PMC10834300 DOI: 10.1016/j.bmc.2023.117330] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/28/2023] [Accepted: 05/10/2023] [Indexed: 05/26/2023]
Abstract
Previously, 1-((4-(4-bromophenyl)-1H-imidazol-2-yl)methyl)-3-(5-(pyridin-2-ylthio)thiazol-2-yl)urea bearing a p-bromine substitution was shown to possess selective inhibitory activity against the Clostridioides difficile enoyl-acyl carrier protein (ACP) reductase II enzyme, FabK. Inhibition of CdFabK by this compound translated to promising antibacterial activity in the low micromolar range. In these studies, we sought to expand our knowledge of the SAR of the phenylimidazole CdFabK inhibitor series while improving the potency of the compounds. Three main series of compounds were synthesized and evaluated based on: 1) pyridine head group modifications including the replacement with a benzothiazole moiety, 2) linker explorations, and 3) phenylimidazole tail group modifications. Overall, improvement in the CdFabK inhibition was achieved, while maintaining the whole cell antibacterial activity. Specifically, compounds 1-((4-(4-bromophenyl)-1H-imidazol-2-yl)methyl)-3-(5-((3-(trifluoromethyl)pyridin-2-yl)thio)thiazol-2-yl)urea, 1-((4-(4-bromophenyl)-1H-imidazol-2-yl)methyl)-3-(6-(trifluoromethyl)benzo[d]thiazol-2-yl)urea, and 1-((4-(4-bromophenyl)-1H-imidazol-2-yl)methyl)-3-(6-chlorobenzo[d]thiazol-2-yl)urea showed CdFabK inhibition (IC50 = 0.10 to 0.24 μM), a 5 to 10-fold improvement in biochemical activity relative to 1-((4-(4-bromophenyl)-1H-imidazol-2-yl)methyl)-3-(5-(pyridin-2-ylthio)thiazol-2-yl)urea, with anti-C. difficile activity ranging from 1.56 to 6.25 μg/mL. Detailed analysis of the expanded SAR, supported by computational analysis, is presented.
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Affiliation(s)
- Krissada Norseeda
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, HI 96720, United States
| | - Fahad Bin Aziz Pavel
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Jacob T Rutherford
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, United States
| | - Humna N Meer
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, United States
| | - Chetna Dureja
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, United States
| | - Julian G Hurdle
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, United States
| | - Kirk E Hevener
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163, United States.
| | - Dianqing Sun
- Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, HI 96720, United States.
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16
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Subramanian C, Frank MW, Yun MK, Rock CO. The Phospholipase A1 Activity of Glycerol Ester Hydrolase (Geh) Is Responsible for Extracellular 2-12( S)-Methyltetradecanoyl-Lysophosphatidylglycerol Production in Staphylococcus aureus. mSphere 2023; 8:e0003123. [PMID: 36976028 PMCID: PMC10117073 DOI: 10.1128/msphere.00031-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 03/07/2023] [Indexed: 03/29/2023] Open
Abstract
Phosphatidylglycerol (PG) is the major membrane phospholipid of Staphylococcus aureus and predominately consists of molecular species with ≥16-carbon acyl chains in the 1-position and anteiso 12(S)-methyltetradecaonate (a15) esterified at the 2-position. The analysis of the growth media for PG-derived products shows S. aureus releases essentially pure 2-12(S)-methyltetradecanoyl-sn-glycero-3-phospho-1'-sn-glycerol (a15:0-LPG) derived from the hydrolysis of the 1-position of PG into the environment. The cellular lysophosphatidylglycerol (LPG) pool is dominated by a15-LPG but also consists of ≥16-LPG species arising from the removal of the 2-position. Mass tracing experiments confirmed a15-LPG was derived from isoleucine metabolism. A screen of candidate secreted lipase knockout strains pinpointed glycerol ester hydrolase (geh) as the gene required for generating extracellular a15-LPG, and complementation of a Δgeh strain with a Geh expression plasmid restored extracellular a15-LPG formation. Orlistat, a covalent inhibitor of Geh, also attenuated extracellular a15-LPG accumulation. Purified Geh hydrolyzed the 1-position acyl chain of PG and generated only a15-LPG from a S. aureus lipid mixture. The Geh product was 2-a15-LPG, which spontaneously isomerizes with time to a mixture of 1- and 2-a15-LPG. Docking PG in the Geh active site provides a structural rationale for the positional specificity of Geh. These data demonstrate a physiological role for Geh phospholipase A1 activity in S. aureus membrane phospholipid turnover. IMPORTANCE Glycerol ester hydrolase, Geh, is an abundant secreted lipase whose expression is controlled by the accessory gene regulator (Agr) quorum-sensing signal transduction pathway. Geh is thought to have a role in virulence based on its ability to hydrolyze host lipids at the infection site to provide fatty acids for membrane biogenesis and substrates for oleate hydratase, and Geh inhibits immune cell activation by hydrolyzing lipoprotein glycerol esters. The discovery that Geh is the major contributor to the formation and release of a15-LPG reveals an unappreciated physiological role for Geh acting as a phospholipase A1 in the degradation of S. aureus membrane phosphatidylglycerol. The role(s) for extracellular a15-LPG in S. aureus biology remain to be elucidated.
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Affiliation(s)
- Chitra Subramanian
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Matthew W. Frank
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - My-Kyung Yun
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Charles O. Rock
- Department of Infectious Diseases, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
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17
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Whaley SG, Frank MW, Rock CO. A short-chain acyl-CoA synthetase that supports branched-chain fatty acid synthesis in Staphylococcus aureus. J Biol Chem 2023; 299:103036. [PMID: 36806679 PMCID: PMC10026030 DOI: 10.1016/j.jbc.2023.103036] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 01/24/2023] [Accepted: 02/09/2023] [Indexed: 02/18/2023] Open
Abstract
Staphylococcus aureus controls its membrane biophysical properties using branched-chain fatty acids (BCFAs). The branched-chain acyl-CoA precursors, utilized to initiate fatty acid synthesis, are derived from branched-chain ketoacid dehydrogenase (Bkd), a multiprotein complex that converts α-keto acids to their corresponding acyl-CoAs; however, Bkd KO strains still contain BCFAs. Here, we show that commonly used rich medias contain substantial concentrations of short-chain acids, like 2-methylbutyric and isobutyric acids, that are incorporated into membrane BCFAs. Bkd-deficient strains cannot grow in defined medium unless it is supplemented with either 2-methylbutyric or isobutyric acid. We performed a screen of candidate KO strains and identified the methylbutyryl-CoA synthetase (mbcS gene; SAUSA300_2542) as required for the incorporation of 2-methylbutyric and isobutyric acids into phosphatidylglycerol. Our mass tracing experiments show that isobutyric acid is converted to isobutyryl-CoA that flows into the even-chain acyl-acyl carrier protein intermediates in the type II fatty acid biosynthesis elongation cycle. Furthermore, purified MbcS is an ATP-dependent acyl-CoA synthetase that selectively catalyzes the activation of 2-methylbutyrate and isobutyrate. We found that butyrate and isovalerate are poor MbcS substrates and activity was not detected with acetate or short-chain dicarboxylic acids. Thus, MbcS functions to convert extracellular 2-methylbutyric and isobutyric acids to their respective acyl-CoAs that are used by 3-ketoacyl-ACP synthase III (FabH) to initiate BCFA biosynthesis.
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Affiliation(s)
- Sarah G Whaley
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Matthew W Frank
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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18
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Greenfield ML, Martin LM, Joodaki F. Computing Individual Area per Head Group Reveals Lipid Bilayer Dynamics. J Phys Chem B 2022; 126:10697-10711. [PMID: 36475708 DOI: 10.1021/acs.jpcb.2c04633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Lipid bilayers express a range of phases from solid-like to gel-like to liquid-like as a function of temperature and lipid surface concentration. The area occupied per lipid head group serves as one useful indicator of the bilayer phase, in conjunction with the two-dimensional radial distribution function (i.e., structure factor) within the bilayer. Typically, the area per head group is determined by dividing the bilayer area equally among all head groups. Such an approach is less satisfactory for a multicomponent set of diverse lipids. In this work, area determination is performed on a lipid-by-lipid basis by attributing to a lipid the volume that surrounds each atom. Voronoi tessellation provides this division of the interfacial region on a per-atom basis. The method is applied to a multicomponent system of water, NaCl, and 19 phospholipid types that was devised recently [Langmuir2022, 38, 9481-9499] as a computational representation of the Gram-positive Staphylococcus aureus phospholipid bilayer. Results demonstrate that lipids and water molecules occupy similar extents of area within the interfacial region; ascribing area only to head groups implicitly incorporates assumptions about head group hydration. Results further show that lipid tails provide non-negligible contributions to area on the membrane side of the bilayer-water interface. Results for minimum and maximum area of individual lipids reveal that spontaneous fluctuations displace head groups more than 10 Å from the interfacial region during an NPT simulation at 310 K, leading to a zero contribution to total area at some times. Total area fluctuations and fluctuations per individual lipid relax with a correlation time of ∼10 ns. The method complements density profile as an approach to quantify the structure and dynamics of computational lipid bilayers.
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Affiliation(s)
- Michael L Greenfield
- Department of Chemical Engineering, 360 Fascitelli Center for Advanced Engineering, University of Rhode Island, Kingston, Rhode Island02881, United States
| | - Lenore M Martin
- Department of Cell and Molecular Biology, University of Rhode Island, 120 Flagg Road, Kingston, Rhode Island02881, United States
| | - Faramarz Joodaki
- Department of Chemical Engineering, 360 Fascitelli Center for Advanced Engineering, University of Rhode Island, Kingston, Rhode Island02881, United States
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19
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Wang D, Mi T, Huang J, Zhou R, Jin Y, Wu C. Metabolomics analysis of salt tolerance of Zygosaccharomyces rouxii and guided exogenous fatty acid addition for improved salt tolerance. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:6263-6272. [PMID: 35510311 DOI: 10.1002/jsfa.11975] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 03/09/2022] [Accepted: 05/04/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Zygosaccharomyces rouxii plays an irreplaceable role in the manufacture of traditional fermented foods, which are produced in a high-salt environment. However, there is little research on strategies for improving salt tolerance of Z. rouxii. RESULTS In this study, metabolomics was used to reveal the changes in intracellular metabolites under salt stress, and the results show that most of the carbohydrate contents decreased, the contents of xanthohumol and glycerol increased (fold change 4.07 and 5.35, respectively), while the contents of galactinol, xylitol and d-threitol decreased (fold change -9.43, -5.83 and -3.59, respectively). In addition, the content of four amino acids and six organic acids decreased, while that of the ten nucleotides increased. Notably, except for stearic acid (C18:0), all fatty acid contents increased. Guided by the metabolomics results, the effect of addition of seven exogenous fatty acids (C12:0, C14:0, C16:0, C18:0, C16:1, C18:1, and C18:2) on the salt tolerance of Z. rouxii was analyzed, and the results suggested that four exogenous fatty acids (C12:0, C16:0, C16:1, and C18:1) can increase the biomass yield and maximum growth rate. Physiological analyses demonstrated that exogenous fatty acids could regulate the distribution of fatty acids in the cell membrane, increase the degree of unsaturation, improve membrane fluidity, and maintain cell integrity, morphology and surface roughness. CONCLUSION These results are applicable to revealing the metabolic mechanisms of Z. rouxii under salt stress and screening potential protective agents to improve stress resistance by adding exogenous fatty acids. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Dingkang Wang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Ting Mi
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Jun Huang
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Rongqing Zhou
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Yao Jin
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Chongde Wu
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
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20
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Abstract
Antibiotic resistance is a serious public health concern, and new drugs are needed to ensure effective treatment of many bacterial infections. Bacterial type II fatty acid synthesis (FASII) is a vital aspect of bacterial physiology, not only for the formation of membranes but also to produce intermediates used in vitamin production. Nature has evolved a repertoire of antibiotics inhibiting different aspects of FASII, validating these enzymes as potential targets for new antibiotic discovery and development. However, significant obstacles have been encountered in the development of FASII antibiotics, and few FASII drugs have advanced beyond the discovery stage. Most bacteria are capable of assimilating exogenous fatty acids. In some cases they can dispense with FASII if fatty acids are present in the environment, making the prospects for identifying broad-spectrum drugs against FASII targets unlikely. Single-target, pathogen-specific FASII drugs appear the best option, but a major drawback to this approach is the rapid acquisition of resistance via target missense mutations. This complication can be mitigated during drug development by optimizing the compound design to reduce the potential impact of on-target missense mutations at an early stage in antibiotic discovery. The lessons learned from the difficulties in FASII drug discovery that have come to light over the last decade suggest that a refocused approach to designing FASII inhibitors has the potential to add to our arsenal of weapons to combat resistance to existing antibiotics.
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Affiliation(s)
- Christopher D Radka
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; ,
| | - Charles O Rock
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA; ,
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21
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Shi Y, Zang N, Lou N, Xu Y, Sun J, Huang M, Zhang H, Lu H, Zhou C, Feng Y. Structure and mechanism for streptococcal fatty acid kinase (Fak) system dedicated to host fatty acid scavenging. SCIENCE ADVANCES 2022; 8:eabq3944. [PMID: 36054360 PMCID: PMC10848957 DOI: 10.1126/sciadv.abq3944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
Staphylococcus and Streptococcus, two groups of major human pathogens, are equipped with a fatty acid kinase (Fak) machinery to scavenge host fatty acids. The Fak complex is contains an ATP-binding subunit FakA, which interacts with varied FakB isoforms, and synthesizes acyl-phosphate from extracellular fatty acids. However, how FakA recognizes its FakB partners and then activates different fatty acids is poorly understood. Here, we systematically describe the Fak system from the zoonotic pathogen, Streptococcus suis. The crystal structure of SsFakA complexed with SsFakB2 was determined at 2.6 Å resolution. An in vitro system of Fak-PlsX (phosphate: acyl-ACP transacylase) was developed to track acyl-phosphate intermediate and its final product acyl-ACP. Structure-guided mutagenesis enabled us to characterize a mechanism for streptococcal FakA working with FakB partners engaged in host fatty acid scavenging. These findings offer a comprehensive description of the Fak kinase machinery, thus advancing the discovery of attractive targets against deadly infections with Streptococcus.
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Affiliation(s)
- Yu Shi
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Ning Zang
- Department of Toxicology, School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Ningjie Lou
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yongchang Xu
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jingdu Sun
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Man Huang
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Huimin Zhang
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Huijie Lu
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Chun Zhou
- Department of Toxicology, School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Youjun Feng
- Departments of Microbiology and General Intensive Care Unit of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
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22
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Parker E, Cain BN, Hajian B, Ulrich RJ, Geddes EJ, Barkho S, Lee HY, Williams JD, Raynor M, Caridha D, Zaino A, Shekhar M, Muñoz KA, Rzasa KM, Temple ER, Hunt D, Jin X, Vuong C, Pannone K, Kelly AM, Mulligan MP, Lee KK, Lau GW, Hung DT, Hergenrother PJ. An Iterative Approach Guides Discovery of the FabI Inhibitor Fabimycin, a Late-Stage Antibiotic Candidate with In Vivo Efficacy against Drug-Resistant Gram-Negative Infections. ACS CENTRAL SCIENCE 2022; 8:1145-1158. [PMID: 36032774 PMCID: PMC9413440 DOI: 10.1021/acscentsci.2c00598] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Indexed: 05/13/2023]
Abstract
Genomic studies and experiments with permeability-deficient strains have revealed a variety of biological targets that can be engaged to kill Gram-negative bacteria. However, the formidable outer membrane and promiscuous efflux pumps of these pathogens prevent many candidate antibiotics from reaching these targets. One such promising target is the enzyme FabI, which catalyzes the rate-determining step in bacterial fatty acid biosynthesis. Notably, FabI inhibitors have advanced to clinical trials for Staphylococcus aureus infections but not for infections caused by Gram-negative bacteria. Here, we synthesize a suite of FabI inhibitors whose structures fit permeation rules for Gram-negative bacteria and leverage activity against a challenging panel of Gram-negative clinical isolates as a filter for advancement. The compound to emerge, called fabimycin, has impressive activity against >200 clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii, and does not kill commensal bacteria. X-ray structures of fabimycin in complex with FabI provide molecular insights into the inhibition. Fabimycin demonstrates activity in multiple mouse models of infection caused by Gram-negative bacteria, including a challenging urinary tract infection model. Fabimycin has translational promise, and its discovery provides additional evidence that antibiotics can be systematically modified to accumulate in Gram-negative bacteria and kill these problematic pathogens.
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Affiliation(s)
- Erica
N. Parker
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Brett N. Cain
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Behnoush Hajian
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Rebecca J. Ulrich
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Emily J. Geddes
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Sulyman Barkho
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Hyang Yeon Lee
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - John D. Williams
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Malik Raynor
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Diana Caridha
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Angela Zaino
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Mrinal Shekhar
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Kristen A. Muñoz
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Kara M. Rzasa
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Emily R. Temple
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Diana Hunt
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department
of Molecular Biology and Center for Computational and Integrative
Biology, Massachusetts General Hospital, Boston, Massachusetts 02115, United States
| | - Xiannu Jin
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Chau Vuong
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Kristina Pannone
- Walter
Reed Army Institute of Research, Silver Spring, Maryland 20910 United States
| | - Aya M. Kelly
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Michael P. Mulligan
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Katie K. Lee
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
| | - Gee W. Lau
- Department
of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
| | - Deborah T. Hung
- Broad
Institute of MIT and Harvard, Cambridge, Massachusetts 02142, United States
- Department
of Molecular Biology and Center for Computational and Integrative
Biology, Massachusetts General Hospital, Boston, Massachusetts 02115, United States
| | - Paul J. Hergenrother
- Department
of Chemistry and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana−Champaign, Urbana, Illinois 61801, United States
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23
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Joodaki F, Martin LM, Greenfield ML. Generation and Computational Characterization of a Complex Staphylococcus aureus Lipid Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:9481-9499. [PMID: 35901279 DOI: 10.1021/acs.langmuir.2c00483] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Studies indicate a crucial cell membrane role in the antibiotic resistance of Staphylococcus aureus. To simulate its membrane structure and dynamics, a complex molecular-scale computational representation of the S. aureus lipid bilayer was developed. Phospholipid types and their amounts were optimized by reverse Monte Carlo to represent characterization data from the literature, leading to 19 different phospholipid types that combine three headgroups [phosphatidylglycerol, lysyl-phosphatidylglycerol (LPG), and cardiolipin] and 10 tails, including iso- and anteiso-branched saturated chains. The averaged lipid bilayer thickness was 36.7 Å, and area per headgroup was 67.8 Å2. Phosphorus and nitrogen density profiles showed that LPG headgroups tended to be bent and oriented more parallel to the bilayer plane. The water density profile showed that small amounts reached the membrane center. Carbon density profiles indicated hydrophobic interactions for all lipids in the middle of the bilayer. Bond vector order parameters along each tail demonstrated different C-H ordering even within distinct lipids of the same type; however, all tails followed similar trends in average order parameter. These complex simulations further revealed bilayer insights beyond those attainable with monodisperse, unbranched lipids. Longer tails often extended into the opposite leaflet. Carbon at and beyond a branch showed significantly decreased ordering compared to carbon in unbranched tails; this feature arose in every branched lipid. Diverse tail lengths distributed these disordered methyl groups throughout the middle third of the bilayer. Distributions in mobility and ordering reveal diverse properties that cannot be obtained with monodisperse lipids.
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Affiliation(s)
- Faramarz Joodaki
- Department of Chemical Engineering, University of Rhode Island, 360 Fascitelli Center for Advanced Engineering, Kingston, Rhode Island 02881, United States
| | - Lenore M Martin
- Department of Cell and Molecular Biology, University of Rhode Island, 120 Flagg Road, Kingston, Rhode Island 02881, United States
| | - Michael L Greenfield
- Department of Chemical Engineering, University of Rhode Island, 360 Fascitelli Center for Advanced Engineering, Kingston, Rhode Island 02881, United States
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24
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Hopf FSM, Roth CD, de Souza EV, Galina L, Czeczot AM, Machado P, Basso LA, Bizarro CV. Bacterial Enoyl-Reductases: The Ever-Growing List of Fabs, Their Mechanisms and Inhibition. Front Microbiol 2022; 13:891610. [PMID: 35814645 PMCID: PMC9260719 DOI: 10.3389/fmicb.2022.891610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
Enoyl-ACP reductases (ENRs) are enzymes that catalyze the last step of the elongation cycle during fatty acid synthesis. In recent years, new bacterial ENR types were discovered, some of them with structures and mechanisms that differ from the canonical bacterial FabI enzymes. Here, we briefly review the diversity of structural and catalytic properties of the canonical FabI and the new FabK, FabV, FabL, and novel ENRs identified in a soil metagenome study. We also highlight recent efforts to use the newly discovered Fabs as targets for drug development and consider the complex evolutionary history of this diverse set of bacterial ENRs.
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Affiliation(s)
- Fernanda S. M. Hopf
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
- Programa de Pós-Graduação em Biologia Celular e Molecular, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Candida D. Roth
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
| | - Eduardo V. de Souza
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
- Programa de Pós-Graduação em Biologia Celular e Molecular, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Luiza Galina
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
- Programa de Pós-Graduação em Medicina e Ciências da Saúde, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Alexia M. Czeczot
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
- Programa de Pós-Graduação em Medicina e Ciências da Saúde, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Pablo Machado
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
- Programa de Pós-Graduação em Biologia Celular e Molecular, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Luiz A. Basso
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
- Programa de Pós-Graduação em Biologia Celular e Molecular, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
- Programa de Pós-Graduação em Medicina e Ciências da Saúde, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
| | - Cristiano V. Bizarro
- Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) and Instituto Nacional de Ciência e Tecnologia em Tuberculose (INCT-TB), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil
- Programa de Pós-Graduação em Biologia Celular e Molecular, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil
- *Correspondence: Cristiano V. Bizarro,
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25
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Flegler A, Iswara J, Mänz AT, Schocke FS, Faßbender WA, Hölzl G, Lipski A. Exogenous fatty acids affect membrane properties and cold adaptation of Listeria monocytogenes. Sci Rep 2022; 12:1499. [PMID: 35087150 PMCID: PMC8795206 DOI: 10.1038/s41598-022-05548-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/11/2022] [Indexed: 12/17/2022] Open
Abstract
Listeria monocytogenes is a food-borne pathogen that can grow at very low temperatures close to the freezing point of food and other matrices. Maintaining cytoplasmic membrane fluidity by changing its lipid composition is indispensable for growth at low temperatures. Its dominant adaptation is to shorten the fatty acid chain length and, in some strains, increase in addition the menaquinone content. To date, incorporation of exogenous fatty acid was not reported for Listeria monocytogenes. In this study, the membrane fluidity grown under low-temperature conditions was affected by exogenous fatty acids incorporated into the membrane phospholipids of the bacterium. Listeria monocytogenes incorporated exogenous fatty acids due to their availability irrespective of their melting points. Incorporation was demonstrated by supplementation of the growth medium with polysorbate 60, polysorbate 80, and food lipid extracts, resulting in a corresponding modification of the membrane fatty acid profile. Incorporated exogenous fatty acids had a clear impact on the fitness of the Listeria monocytogenes strains, which was demonstrated by analyses of the membrane fluidity, resistance to freeze-thaw stress, and growth rates. The fatty acid content of the growth medium or the food matrix affects the membrane fluidity and thus proliferation and persistence of Listeria monocytogenes in food under low-temperature conditions.
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Affiliation(s)
- Alexander Flegler
- Department of Food Microbiology and Hygiene, Institute of Nutritional and Food Science (IEL), University of Bonn, 53115, Bonn, Germany
| | - Janice Iswara
- Department of Food Microbiology and Hygiene, Institute of Nutritional and Food Science (IEL), University of Bonn, 53115, Bonn, Germany
| | - Anna Tatjana Mänz
- Department of Food Microbiology and Hygiene, Institute of Nutritional and Food Science (IEL), University of Bonn, 53115, Bonn, Germany
| | - Frieda Sophia Schocke
- Department of Food Microbiology and Hygiene, Institute of Nutritional and Food Science (IEL), University of Bonn, 53115, Bonn, Germany
| | - Wanda Antonia Faßbender
- Department of Food Microbiology and Hygiene, Institute of Nutritional and Food Science (IEL), University of Bonn, 53115, Bonn, Germany
| | - Georg Hölzl
- Department of Molecular Biotechnology, Institute of Molecular Physiology and Biotechnology of Plants (IMBIO), University of Bonn, 53115, Bonn, Germany
| | - André Lipski
- Department of Food Microbiology and Hygiene, Institute of Nutritional and Food Science (IEL), University of Bonn, 53115, Bonn, Germany.
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26
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Craft MK, Waldrop GL. Mechanism of biotin carboxylase inhibition by ethyl 4-[[2-chloro-5-(phenylcarbamoyl)phenyl]sulphonylamino]benzoate. J Enzyme Inhib Med Chem 2021; 37:100-108. [PMID: 34894987 PMCID: PMC8667948 DOI: 10.1080/14756366.2021.1994558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
The rise of antibacterial-resistant bacteria is a major problem in the United States of America and around the world. Millions of patients are infected with antimicrobial resistant bacteria each year. Novel antibacterial agents are needed to combat the growing and present crisis. Acetyl-CoA carboxylase (ACC), the multi-subunit complex which catalyses the first committed step in fatty acid synthesis, is a validated target for antibacterial agents. However, there are at present, no commercially available antibiotics that target ACC. Ethyl 4-[[2-chloro-5-(phenylcarbamoyl)phenyl]sulfonylamino]benzoate (SABA1) is a compound that has been shown to have antibacterial properties against Pseudomonas aeruginosa and Escherichia coli. SABA1 inhibits biotin carboxylase (BC), the enzyme that catalyses the first half reaction of ACC. SABA1 inhibits BC via an atypical mechanism. It binds in the biotin binding site in the presence of ADP. SABA1 represents a potentially new class of antibiotics that can be used to combat the antibacterial resistance crisis.
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Affiliation(s)
- Matthew K Craft
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Grover L Waldrop
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
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27
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Frank MW, Whaley SG, Rock CO. Branched-chain amino acid metabolism controls membrane phospholipid structure in Staphylococcus aureus. J Biol Chem 2021; 297:101255. [PMID: 34592315 PMCID: PMC8524195 DOI: 10.1016/j.jbc.2021.101255] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/12/2021] [Accepted: 09/14/2021] [Indexed: 11/30/2022] Open
Abstract
Branched-chain amino acids (primarily isoleucine) are important regulators of virulence and are converted to precursor molecules used to initiate fatty acid synthesis in Staphylococcus aureus. Defining how bacteria control their membrane phospholipid composition is key to understanding their adaptation to different environments. Here, we used mass tracing experiments to show that extracellular isoleucine is preferentially metabolized by the branched-chain ketoacid dehydrogenase complex, in contrast to valine, which is not efficiently converted to isobutyryl-CoA. This selectivity creates a ratio of anteiso:iso C5-CoAs that matches the anteiso:iso ratio in membrane phospholipids, indicating indiscriminate utilization of these precursors by the initiation condensing enzyme FabH. Lipidomics analysis showed that removal of isoleucine and leucine from the medium led to the replacement of phospholipid molecular species containing anteiso/iso 17- and 19-carbon fatty acids with 18- and 20-carbon straight-chain fatty acids. This compositional change is driven by an increase in the acetyl-CoA:C5-CoA ratio, enhancing the utilization of acetyl-CoA by FabH. The acyl carrier protein (ACP) pool normally consists of odd carbon acyl-ACP intermediates, but when branched-chain amino acids are absent from the environment, there was a large increase in even carbon acyl-ACP pathway intermediates. The high substrate selectivity of PlsC ensures that, in the presence or the absence of extracellular Ile/Leu, the 2-position is occupied by a branched-chain 15-carbon fatty acid. These metabolomic measurements show how the metabolism of isoleucine and leucine, rather than the selectivity of FabH, control the structure of membrane phospholipids.
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Affiliation(s)
- Matthew W Frank
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Sarah G Whaley
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St Jude Children's Research Hospital, Memphis, Tennessee, USA.
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28
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Wang D, Chen H, Yang H, Yao S, Wu C. Incorporation of Exogenous Fatty Acids Enhances the Salt Tolerance of Food Yeast Zygosaccharomyces rouxii. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:10301-10310. [PMID: 34449211 DOI: 10.1021/acs.jafc.1c03896] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Fatty acids have great effects on the maintenance of the cell membrane structure, cell viability, and cell metabolisms. In this study, we sought to elucidate the effects of exogenous fatty acids on the salt tolerance of food yeast Zygosaccharomyces rouxii. Results showed that Z. rouxii can grow by using exogenous fatty acids (C12:0, C14:0, C16:0, C16:1, C18:0, C18:1, and C18:2) as the sole carbon source. Four fatty acids (C12:0, C16:0, C16:1, and C18:1) can improve the salt tolerance of cells, enhance the formation of the cell biofilm, regulate the chemical compositions, restore growth in the presence of cerulenin, regulate the contents of membrane fatty acids, and control the expression of key genes in the fatty acid metabolism. Our results reveal that Z. rouxii can synthesize membrane fatty acids from exogenous fatty acids and the supplementation of these fatty acids can override the need for de novo fatty acid biosynthesis.
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Affiliation(s)
- Dingkang Wang
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China
| | - Hong Chen
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China
| | - Huan Yang
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China
| | - Shangjie Yao
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China
| | - Chongde Wu
- College of Biomass Science and Engineering, Sichuan University, Chengdu 610065, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu 610065, China
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29
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Chen X, Teoh WP, Stock MR, Resko ZJ, Alonzo F. Branched chain fatty acid synthesis drives tissue-specific innate immune response and infection dynamics of Staphylococcus aureus. PLoS Pathog 2021; 17:e1009930. [PMID: 34496007 PMCID: PMC8452012 DOI: 10.1371/journal.ppat.1009930] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/20/2021] [Accepted: 08/30/2021] [Indexed: 12/13/2022] Open
Abstract
Fatty acid-derived acyl chains of phospholipids and lipoproteins are central to bacterial membrane fluidity and lipoprotein function. Though it can incorporate exogenous unsaturated fatty acids (UFA), Staphylococcus aureus synthesizes branched chain fatty acids (BCFA), not UFA, to modulate or increase membrane fluidity. However, both endogenous BCFA and exogenous UFA can be attached to bacterial lipoproteins. Furthermore, S. aureus membrane lipid content varies based upon the amount of exogenous lipid in the environment. Thus far, the relevance of acyl chain diversity within the S. aureus cell envelope is limited to the observation that attachment of UFA to lipoproteins enhances cytokine secretion by cell lines in a TLR2-dependent manner. Here, we leveraged a BCFA auxotroph of S. aureus and determined that driving UFA incorporation disrupted infection dynamics and increased cytokine production in the liver during systemic infection of mice. In contrast, infection of TLR2-deficient mice restored inflammatory cytokines and bacterial burden to wildtype levels, linking the shift in acyl chain composition toward UFA to detrimental immune activation in vivo. In in vitro studies, bacterial lipoproteins isolated from UFA-supplemented cultures were resistant to lipase-mediated ester hydrolysis and exhibited heightened TLR2-dependent innate cell activation, whereas lipoproteins with BCFA esters were completely inactivated after lipase treatment. These results suggest that de novo synthesis of BCFA reduces lipoprotein-mediated TLR2 activation and improves lipase-mediated hydrolysis making it an important determinant of innate immunity. Overall, this study highlights the potential relevance of cell envelope acyl chain repertoire in infection dynamics of bacterial pathogens.
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Affiliation(s)
- Xi Chen
- Department of Microbiology and Immunology, Loyola University Chicago–Stritch School of Medicine, Maywood, Illinois, United States of America
| | - Wei Ping Teoh
- Department of Microbiology and Immunology, Loyola University Chicago–Stritch School of Medicine, Maywood, Illinois, United States of America
| | - Madison R. Stock
- Department of Microbiology and Immunology, Loyola University Chicago–Stritch School of Medicine, Maywood, Illinois, United States of America
| | - Zachary J. Resko
- Department of Microbiology and Immunology, Loyola University Chicago–Stritch School of Medicine, Maywood, Illinois, United States of America
| | - Francis Alonzo
- Department of Microbiology and Immunology, Loyola University Chicago–Stritch School of Medicine, Maywood, Illinois, United States of America
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Freeman C, Hynds HM, Carpenter JM, Appala K, Bimpeh K, Barbarek S, Gatto C, Wilkinson BJ, Hines KM. Revealing Fatty Acid Heterogeneity in Staphylococcal Lipids with Isotope Labeling and RPLC-IM-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:2376-2385. [PMID: 34014662 DOI: 10.1021/jasms.1c00092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Up to 80% of the fatty acids in Staphylococcus aureus membrane lipids are branched, rather than straight-chain, fatty acids. The branched fatty acids (BCFAs) may have either an even or odd number of carbons, and the branch position may be at the penultimate carbon (iso) or the antepenultimate (anteiso) carbon of the tail. This results in two sets of isomeric fatty acid species with the same number of carbons that cannot be resolved by mass spectrometry. The isomer/isobar challenge is further complicated when the mixture of BCFAs and straight-chain fatty acids (SCFAs) are esterified into diacylated lipids such as the phosphatidylglycerol (PG) species of the S. aureus membrane. No conventional chromatographic method has been able to resolve diacylated lipids containing mixtures of SCFAs, anteiso-odd, iso-odd, and iso-even BCFAs. A major hurdle to method development in this area is the lack of relevant analytical standards for lipids containing BCFA isomers. The diversity of the S. aureus lipidome and its naturally high levels of BCFAs present an opportunity to explore the potential of resolving diacylated lipids containing BCFAs and SFCAs. Using our knowledge of lipid and fatty acid biosynthesis in S. aureus, we have used a stable-isotope-labeling strategy to develop and validate a 30 min C18 reversed-phase liquid chromatography method combined with traveling-wave ion mobility-mass spectrometry to provide resolution of diacylated lipids based on the number of BCFAs that they contain.
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Affiliation(s)
- Christian Freeman
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Hannah M Hynds
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Jana M Carpenter
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Keerthi Appala
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Kingsley Bimpeh
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Shannon Barbarek
- School of Biological Sciences, Illinois State University, Normal, Illinois 61790, United States
| | - Craig Gatto
- School of Biological Sciences, Illinois State University, Normal, Illinois 61790, United States
| | - Brian J Wilkinson
- School of Biological Sciences, Illinois State University, Normal, Illinois 61790, United States
| | - Kelly M Hines
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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Staphylococcus aureus adapts to the host nutritional landscape to overcome tissue-specific branched-chain fatty acid requirement. Proc Natl Acad Sci U S A 2021; 118:2022720118. [PMID: 33753501 DOI: 10.1073/pnas.2022720118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During infection, pathogenic microbes adapt to the nutritional milieu of the host through metabolic reprogramming and nutrient scavenging. For the bacterial pathogen Staphylococcus aureus, virulence in diverse infection sites is driven by the ability to scavenge myriad host nutrients, including lipoic acid, a cofactor required for the function of several critical metabolic enzyme complexes. S. aureus shuttles lipoic acid between these enzyme complexes via the amidotransferase, LipL. Here, we find that acquisition of lipoic acid, or its attachment via LipL to enzyme complexes required for the generation of acetyl-CoA and branched-chain fatty acids, is essential for bacteremia, yet dispensable for skin infection in mice. A lipL mutant is auxotrophic for carboxylic acid precursors required for synthesis of branched-chain fatty acids, an essential component of staphylococcal membrane lipids and the agent of membrane fluidity. However, the skin is devoid of branched-chain fatty acids. We showed that S. aureus instead scavenges host-derived unsaturated fatty acids from the skin using the secreted lipase, Geh, and the unsaturated fatty acid-binding protein, FakB2. Moreover, murine infections demonstrated the relevance of host lipid assimilation to staphylococcal survival. Altogether, these studies provide insight into an adaptive trait that bypasses de novo lipid synthesis to facilitate S. aureus persistence during superficial infection. The findings also reinforce the inherent challenges associated with targeting bacterial lipogenesis as an antibacterial strategy and support simultaneous inhibition of host fatty acid salvage during treatment.
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Casillas-Vargas G, Ocasio-Malavé C, Medina S, Morales-Guzmán C, Del Valle RG, Carballeira NM, Sanabria-Ríos DJ. Antibacterial fatty acids: An update of possible mechanisms of action and implications in the development of the next-generation of antibacterial agents. Prog Lipid Res 2021; 82:101093. [PMID: 33577909 PMCID: PMC8137538 DOI: 10.1016/j.plipres.2021.101093] [Citation(s) in RCA: 133] [Impact Index Per Article: 44.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/24/2021] [Accepted: 01/26/2021] [Indexed: 12/14/2022]
Abstract
The antibacterial activity of fatty acids (FA) is well known in the literature and represents a promising option for developing the next-generation of antibacterial agents to treat a broad spectrum of bacterial infections. FA are highly involved in living organisms' defense system against numerous pathogens, including multidrug-resistant bacteria. When combined with other antibacterial agents, the remarkable ability of FA to enhance their bactericidal properties is a critical feature that is not commonly observed in other naturally-occurring compounds. More reviews focusing on FA antibacterial activity, traditional and non-traditional mechanisms and biomedical applications are needed. This review is intended to update the reader on the antibacterial properties of recent FA and how their chemical structures influence their antibacterial activity. This review also aims to better understand both traditional and non-traditional mechanisms involved in these recently explored FA antibacterial activities.
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Affiliation(s)
- Giancarlo Casillas-Vargas
- Faculty of Science and Technology, Department of Natural Sciences, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, USA
| | - Carlimar Ocasio-Malavé
- Faculty of Science and Technology, Department of Natural Sciences, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, USA
| | - Solymar Medina
- Faculty of Science and Technology, Department of Natural Sciences, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, USA
| | - Christian Morales-Guzmán
- University of Puerto Rico, Río Piedras Campus, Department of Chemistry, 17 Ave. Universidad Ste. 1701, San Juan, PR 00925-2537, USA
| | - René García Del Valle
- University of Puerto Rico, Río Piedras Campus, Department of Chemistry, 17 Ave. Universidad Ste. 1701, San Juan, PR 00925-2537, USA
| | - Néstor M Carballeira
- University of Puerto Rico, Río Piedras Campus, Department of Chemistry, 17 Ave. Universidad Ste. 1701, San Juan, PR 00925-2537, USA.
| | - David J Sanabria-Ríos
- Faculty of Science and Technology, Department of Natural Sciences, Inter American University of Puerto Rico, Metropolitan Campus, PO Box 191293, San Juan, PR 00919, USA.
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(p)ppGpp/GTP and Malonyl-CoA Modulate Staphylococcus aureus Adaptation to FASII Antibiotics and Provide a Basis for Synergistic Bi-Therapy. mBio 2021; 12:mBio.03193-20. [PMID: 33531402 PMCID: PMC7858065 DOI: 10.1128/mbio.03193-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is a major human bacterial pathogen for which new inhibitors are urgently needed. Antibiotic development has centered on the fatty acid synthesis (FASII) pathway, which provides the building blocks for bacterial membrane phospholipids. Fatty acid biosynthesis (FASII) enzymes are considered valid targets for antimicrobial drug development against the human pathogen Staphylococcus aureus. However, incorporation of host fatty acids confers FASII antibiotic adaptation that compromises prospective treatments. S. aureus adapts to FASII inhibitors by first entering a nonreplicative latency period, followed by outgrowth. Here, we used transcriptional fusions and direct metabolite measurements to investigate the factors that dictate the duration of latency prior to outgrowth. We show that stringent response induction leads to repression of FASII and phospholipid synthesis genes. (p)ppGpp induction inhibits synthesis of malonyl-CoA, a molecule that derepresses FapR, a key regulator of FASII and phospholipid synthesis. Anti-FASII treatment also triggers transient expression of (p)ppGpp-regulated genes during the anti-FASII latency phase, with concomitant repression of FapR regulon expression. These effects are reversed upon outgrowth. GTP depletion, a known consequence of the stringent response, also occurs during FASII latency, and is proposed as the common signal linking these responses. We next showed that anti-FASII treatment shifts malonyl-CoA distribution between its interactants FapR and FabD, toward FapR, increasing expression of the phospholipid synthesis genes plsX and plsC during outgrowth. We conclude that components of the stringent response dictate malonyl-CoA availability in S. aureus FASII regulation, and contribute to latency prior to anti-FASII-adapted outgrowth. A combinatory approach, coupling a (p)ppGpp inducer and an anti-FASII, blocks S. aureus outgrowth, opening perspectives for bi-therapy treatment.
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Lin L, Su Z, Li Y, Zhang C. Comparative performance and mechanism of bacterial inactivation induced by metal-free modified g-C 3N 4 under visible light: Escherichia coli versus Staphylococcus aureus. CHEMOSPHERE 2021; 265:129060. [PMID: 33293051 DOI: 10.1016/j.chemosphere.2020.129060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/01/2020] [Accepted: 11/19/2020] [Indexed: 06/12/2023]
Abstract
The inactivation mechanism of pathogenic microorganisms in water needs to be comprehensively explored in order to better guide the development of an effective and green disinfection method for drinking water safety. Here, metal-free modified g-C3N4 was prepared and used to inactivate two typical bacteria (namely, Gram-positive E. coli and Gram-negative S. aureus) in water under visible light from a comparative perspective. These two bacteria could be inactivated in the presence of modified g-C3N4 within 6 h of visible light, but their inactivation kinetics were quite different. E. coli were inactivated slowly in the early disinfection stage and rapidly in the later disinfection stage, whereas S. aureus were inactivated steadily during the entire disinfection process. Moreover, the impacts of important water parameters (pH, salt, temperature, and water matrix) on photocatalytic inactivation of E. coli and S. aureus were also distinct. In addition, scavenger experiments indicated that superoxide radicals played the most important role in E. coli inactivation, while both superoxide and hydroxyl radicals were important for S. aureus inactivation. Quantitative changes in fatty acids, potassium ions, proteins and DNA of the bacterial suspensions suggested that the higher resistance of E. coli in the early inactivation stage could be originated from the difference in the phospholipid repair system in cell membrane structures. This study can provide new insights into research and development of a safe and effective disinfection technology for drinking water.
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Affiliation(s)
- Li Lin
- Key Lab of Basin Water Resource and Eco- Environmental Science in Hubei Province, Basin Water Environmental Research Department, Changjiang River Scientific Research Institute, Huangpu Road #23, Wuhan, 430010, PR China
| | - Ziying Su
- Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Xikang Road #1, Nanjing, 210098, PR China
| | - Yi Li
- Key Laboratory of Integrated Regulation and Resource Development of Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Xikang Road #1, Nanjing, 210098, PR China.
| | - Chi Zhang
- College of Mechanics and Materials, Hohai University, Xikang Road #1, Nanjing, 210098, PR China
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The Bactericidal Fatty Acid Mimetic 2CCA-1 Selectively Targets Pneumococcal Extracellular Polyunsaturated Fatty Acid Metabolism. mBio 2020; 11:mBio.03027-20. [PMID: 33323510 PMCID: PMC7773995 DOI: 10.1128/mbio.03027-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Fatty acid biosynthesis is an attractive antibiotic target, as it affects the supply of membrane phospholipid building blocks. In Streptococcus pneumoniae, it is not sufficient to target only the endogenous fatty acid synthesis machinery, as uptake of host fatty acids may bypass this inhibition. Streptococcus pneumoniae, a major cause of pneumonia, sepsis, and meningitis worldwide, has the nasopharynges of small children as its main ecological niche. Depletion of pneumococci from this niche would reduce the disease burden and could be achieved using small molecules with narrow-spectrum antibacterial activity. We identified the alkylated dicyclohexyl carboxylic acid 2CCA-1 as a potent inducer of autolysin-mediated lysis of S. pneumoniae, while having low activity against Staphylococcus aureus. 2CCA-1-resistant strains were found to have inactivating mutations in fakB3, known to be required for uptake of host polyunsaturated fatty acids, as well as through inactivation of the transcriptional regulator gene fabT, vital for endogenous, de novo fatty acid synthesis regulation. Structure activity relationship exploration revealed that, besides the central dicyclohexyl group, the fatty acid-like structural features of 2CCA-1 were essential for its activity. The lysis-inducing activity of 2CCA-1 was considerably more potent than that of free fatty acids and required growing bacteria, suggesting that 2CCA-1 needs to be metabolized to exert its antimicrobial activity. Total lipid analysis of 2CCA-1 treated bacteria identified unique masses that were modeled to 2CCA-1 containing lysophosphatidic and phosphatidic acid in wild-type but not in fakB3 mutant bacteria. This suggests that 2CCA-1 is metabolized as a fatty acid via FakB3 and utilized as a phospholipid building block, leading to accumulation of toxic phospholipid species. Analysis of FabT-mediated fakB3 expression elucidates how the pneumococcus could ensure membrane homeostasis and concurrent economic use of host-derived fatty acids.
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Abstract
Staphylococcus aureus is a leading agent of antibiotic-resistant bacterial infections in the world. S. aureus tightly controls metal homeostasis during infection, and disruption of metal uptake systems impairs staphylococcal virulence. We identified small molecules that interfere with metal handling in S. aureus to develop chemical probes to investigate metallobiology in this organism. Compound VU0026921 was identified as a small molecule that kills S. aureus both aerobically and anaerobically. The activity of VU0026921 is modulated by metal supplementation, is enhanced by genetic inactivation of Mn homeostasis genes, and correlates with increased cellular reactive oxygen species. Treatment with VU0026921 causes accumulation of multiple metals within S. aureus cells and concomitant upregulation of genes involved in metal detoxification. This work defines a small-molecule probe for further defining the role of metal toxicity in S. aureus and validates future antibiotic development targeting metal toxicity pathways. Metals are essential nutrients that all living organisms acquire from their environment. While metals are necessary for life, excess metal uptake can be toxic; therefore, intracellular metal levels are tightly regulated in bacterial cells. Staphylococcus aureus, a Gram-positive bacterium, relies on metal uptake and metabolism to colonize vertebrates. Thus, we hypothesized that an expanded understanding of metal homeostasis in S. aureus will lead to the discovery of pathways that can be targeted with future antimicrobials. We sought to identify small molecules that inhibit S. aureus growth in a metal-dependent manner as a strategy to uncover pathways that maintain metal homeostasis. Here, we demonstrate that VU0026921 kills S. aureus through disruption of metal homeostasis. VU0026921 activity was characterized through cell culture assays, transcriptional sequencing, compound structure-activity relationship, reactive oxygen species (ROS) generation assays, metal binding assays, and metal level analyses. VU0026921 disrupts metal homeostasis in S. aureus, increasing intracellular accumulation of metals and leading to toxicity through mismetalation of enzymes, generation of reactive oxygen species, or disruption of other cellular processes. Antioxidants partially protect S. aureus from VU0026921 killing, emphasizing the role of reactive oxygen species in the mechanism of killing, but VU0026921 also kills S. aureus anaerobically, indicating that the observed toxicity is not solely oxygen dependent. VU0026921 disrupts metal homeostasis in multiple Gram-positive bacteria, leading to increased reactive oxygen species and cell death, demonstrating the broad applicability of these findings. Further, this study validates VU0026921 as a probe to further decipher mechanisms required to maintain metal homeostasis in Gram-positive bacteria.
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Induction of Daptomycin Tolerance in Enterococcus faecalis by Fatty Acid Combinations. Appl Environ Microbiol 2020; 86:AEM.01178-20. [PMID: 32801181 PMCID: PMC7531955 DOI: 10.1128/aem.01178-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 08/08/2020] [Indexed: 12/14/2022] Open
Abstract
With an increasing prevalence of antibiotic resistance in the clinic, we strive to understand more about microbial defensive mechanisms. A nongenetic tolerance to the antibiotic daptomycin was discovered in Enterococcus faecalis that results in the increased survival of bacterial populations after treatment with the drug. This tolerance mechanism likely synergizes with antibiotic resistance in the clinic. Given that this tolerance phenotype is induced by incorporation of fatty acids present in the host, it can be assumed that infections by this organism require a higher dose of antibiotic for successful eradication. The mixture of fatty acids in human fluids is quite diverse, with little understanding between the interplay of fatty acid combinations and the tolerance phenotype we observe. It is crucial to understand the effects of fatty acid combinations on E. faecalis physiology if we are to suppress the tolerance physiology in the clinic. Enterococcus faecalis is a Gram-positive bacterium that normally exists as an intestinal commensal in humans but is also a leading cause of nosocomial infections. Previous work noted that growth supplementation with serum induced tolerance to membrane-damaging agents, including the antibiotic daptomycin. Specific fatty acids found within serum could independently provide tolerance to daptomycin (protective fatty acids), yet some fatty acids found in serum did not and had negative effects on enterococcal physiology (nonprotective fatty acids). Here, we measured a wide array of physiological responses after supplementation with combinations of protective and nonprotective fatty acids to better understand how serum induces daptomycin tolerance. When cells were supplemented with either nonprotective fatty acid, palmitic acid, or stearic acid, there were marked defects in growth and morphology, but these defects were rescued upon supplementation with either protective fatty acid, oleic acid, or linoleic acid. Membrane fluidity decreased with growth in either palmitic or stearic acid alone but returned to basal levels when a protective fatty acid was supplied. Daptomycin tolerance could be induced if a protective fatty acid was provided with a nonprotective fatty acid, and some specific combinations protected as well as serum supplementation. While cell envelope charge has been associated with tolerance to daptomycin in other Gram-positive bacteria, we concluded that it does not correlate with the fatty acid-induced protection we observed. Based on these observations, we conclude that daptomycin tolerance by serum is driven by specific, protective fatty acids found within the fluid. IMPORTANCE With an increasing prevalence of antibiotic resistance in the clinic, we strive to understand more about microbial defensive mechanisms. A nongenetic tolerance to the antibiotic daptomycin was discovered in Enterococcus faecalis that results in the increased survival of bacterial populations after treatment with the drug. This tolerance mechanism likely synergizes with antibiotic resistance in the clinic. Given that this tolerance phenotype is induced by incorporation of fatty acids present in the host, it can be assumed that infections by this organism require a higher dose of antibiotic for successful eradication. The mixture of fatty acids in human fluids is quite diverse, with little understanding between the interplay of fatty acid combinations and the tolerance phenotype we observe. It is crucial to understand the effects of fatty acid combinations on E. faecalis physiology if we are to suppress the tolerance physiology in the clinic.
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Kénanian G, Morvan C, Weckel A, Pathania A, Anba-Mondoloni J, Halpern D, Gaillard M, Solgadi A, Dupont L, Henry C, Poyart C, Fouet A, Lamberet G, Gloux K, Gruss A. Permissive Fatty Acid Incorporation Promotes Staphylococcal Adaptation to FASII Antibiotics in Host Environments. Cell Rep 2020; 29:3974-3982.e4. [PMID: 31851927 DOI: 10.1016/j.celrep.2019.11.071] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/01/2019] [Accepted: 11/15/2019] [Indexed: 02/08/2023] Open
Abstract
The essentiality of fatty acid synthesis (FASII) products in the human pathogen Staphylococcus aureus is the underlying rationale for FASII-targeted antimicrobial drug design. Reports of anti-FASII efficacy in animals support this choice. However, restricted test conditions used previously led us to investigate this postulate in a broader, host-relevant context. We report that S. aureus rapidly adapts to FASII antibiotics without FASII mutations when exposed to host environments. FASII antibiotic administration upon signs of infection, rather than just after inoculation as commonly practiced, fails to eliminate S. aureus in a septicemia model. In vitro, serum lowers S. aureus membrane stress, leading to a greater retention of the substrates required for environmental fatty acid (eFA) utilization: eFAs and the acyl carrier protein. In this condition, eFA occupies both phospholipid positions, regardless of anti-FASII selection. Our results identify S. aureus membrane plasticity in host environments as a main limitation for using FASII antibiotics in monotherapeutic treatments.
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Affiliation(s)
- Gérald Kénanian
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Claire Morvan
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Antonin Weckel
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, 75014 Paris, France
| | - Amit Pathania
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Jamila Anba-Mondoloni
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - David Halpern
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Marine Gaillard
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, 75014 Paris, France
| | - Audrey Solgadi
- SAMM, UMS IPSIT, Faculté de Pharmacie, Université Paris-Saclay, Chatenay-Malabry, France
| | - Laetitia Dupont
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Céline Henry
- PAPPSO Platform, Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Claire Poyart
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, 75014 Paris, France; Centre National de Référence des Streptocoques, Hôpitaux Universitaires Paris Centre Site Cochin, APHP, Paris, France
| | - Agnès Fouet
- Université de Paris, Institut Cochin, INSERM, U1016, CNRS, UMR8104, 75014 Paris, France
| | - Gilles Lamberet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Karine Gloux
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France
| | - Alexandra Gruss
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy en Josas, France.
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The type VII secretion system protects Staphylococcus aureus against antimicrobial host fatty acids. Sci Rep 2020; 10:14838. [PMID: 32908165 PMCID: PMC7481793 DOI: 10.1038/s41598-020-71653-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/17/2020] [Indexed: 02/06/2023] Open
Abstract
The Staphylococcus aureus type VII secretion system (T7SS) exports several proteins that are pivotal for bacterial virulence. The mechanisms underlying T7SS-mediated staphylococcal survival during infection nevertheless remain unclear. Here we report that S. aureus lacking T7SS components are more susceptible to host-derived antimicrobial fatty acids. Unsaturated fatty acids such as linoleic acid (LA) elicited an increased inhibition of S. aureus mutants lacking T7SS effectors EsxC, EsxA and EsxB, or the membrane-bound ATPase EssC, compared to the wild-type (WT). T7SS mutants generated in different S. aureus strain backgrounds also displayed an increased sensitivity to LA. Analysis of bacterial membrane lipid profiles revealed that the esxC mutant was less able to incorporate LA into its membrane phospholipids. Although the ability to bind labelled LA did not differ between the WT and mutant strains, LA induced more cell membrane damage in the T7SS mutants compared to the WT. Furthermore, proteomic analyses of WT and mutant cell fractions revealed that, in addition to compromising membranes, T7SS defects induce oxidative stress and hamper their response to LA challenge. Thus, our findings indicate that T7SS contribute to maintaining S. aureus membrane integrity and homeostasis when bacteria encounter antimicrobial fatty acids.
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Machinandiarena F, Nakamatsu L, Schujman GE, de Mendoza D, Albanesi D. Revisiting the coupling of fatty acid to phospholipid synthesis in bacteria with FapR regulation. Mol Microbiol 2020; 114:653-663. [PMID: 32671874 DOI: 10.1111/mmi.14574] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/07/2020] [Accepted: 07/11/2020] [Indexed: 12/31/2022]
Abstract
A key aspect in membrane biogenesis is the coordination of fatty acid to phospholipid synthesis rates. In most bacteria, PlsX is the first enzyme of the phosphatidic acid synthesis pathway, the common precursor of all phospholipids. Previously, we proposed that PlsX is a key regulatory point that synchronizes the fatty acid synthase II with phospholipid synthesis in Bacillus subtilis. However, understanding the basis of such coordination mechanism remained a challenge in Gram-positive bacteria. Here, we show that the inhibition of fatty acid and phospholipid synthesis caused by PlsX depletion leads to the accumulation of long-chain acyl-ACPs, the end products of the fatty acid synthase II. Hydrolysis of the acyl-ACP pool by heterologous expression of a cytosolic thioesterase relieves the inhibition of fatty acid synthesis, indicating that acyl-ACPs are feedback inhibitors of this metabolic route. Unexpectedly, inactivation of PlsX triggers a large increase of malonyl-CoA leading to induction of the fap regulon. This finding discards the hypothesis, proposed for B. subtilis and extended to other Gram-positive bacteria, that acyl-ACPs are feedback inhibitors of the acetyl-CoA carboxylase. Finally, we propose that the continuous production of malonyl-CoA during phospholipid synthesis inhibition provides an additional mechanism for fine-tuning the coupling between phospholipid and fatty acid production in bacteria with FapR regulation.
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Affiliation(s)
- Federico Machinandiarena
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Leandro Nakamatsu
- División de Biología Sintética, Ingeniería Metabólica SA (INMET), Rosario, Argentina
| | - Gustavo E Schujman
- División de Biología Sintética, Ingeniería Metabólica SA (INMET), Rosario, Argentina.,CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Diego de Mendoza
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Daniela Albanesi
- Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
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Zahedi M, Asgari Q, Badakhshan F, Sakhteman A, Ranjbar S, Khoshneviszadeh M. Anti- Toxoplasma gondii activity of 5-oxo-hexahydroquinoline derivatives: synthesis, in vitro and in vivo evaluations, and molecular docking analysis. Res Pharm Sci 2020; 15:367-380. [PMID: 33312215 PMCID: PMC7714012 DOI: 10.4103/1735-5362.293515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 04/28/2020] [Accepted: 08/20/2020] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND AND PURPOSE The aim of this study was to evaluate the in vitro and in vivo anti-Toxoplasma gondii (T. gondii) effect of 5-oxo-hexahydroquinoline compounds. Moreover, molecular docking study of the compounds into the active site of enoyl-acyl carrier protein reductase (ENR) as a necessary enzyme for the vitality of apicoplast was carried out. EXPERIMENTAL APPROACH A number of 5-oxo-hexahydoquinoline derivatives (Z1-Z4) were synthesized. The T. gondii tachyzoites of RH strain were treated by different concentrations (1-64 μg/mL) of the compounds. The viability of the encountered parasites with compounds was assessed using flow cytometry and propidium iodide (PI) staining. Due to the high mortality effect of Z3 and Z4 in vitro, their chemotherapy effect was assessed by inoculation of tachyzoites to four BALB/c mice groups (n = 5), followed by the gavage of various concentrations of the compounds to the mice. Molecular docking was done to study the binding affinity of the synthesized 5-oxo-hexahydroquinolines into ENR enzyme active site byusing AutoDock Vina® software. Docking was performed by a Lamarckian Genetic Algorithm with 100 runs. FINDINGS / RESULTS Flow cytometry assay results indicated compounds Z3 and Z4 had relevant mortality effect on parasite tachyzoites. Besides, in vivo experiments were also performed and a partial increase of mice longevity between control and experiment groups was recorded. Molecular docking of Z3 and Z4 in the binding site of ENR enzyme indicated that the compounds were well accommodated within the binding site. Therefore, it could be suggested that these compounds may exert their anti-T. gondii activity through the inhibition of the ENR enzyme. CONCLUSION AND IMPLICATIONS Compounds Z3 and Z4 are good leads in order to develop better anti-T. gondii agents as they demonstrated both in vitro and in vivo inhibitory effects on tachyzoites viability and infection. Further studies on altering the route of administration along with additional pharmacokinetics evaluations are needed to improve the anti-T. gondii impacts of 5-oxo-hexahydroquinoline compounds.
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Affiliation(s)
- Mohammadsaeid Zahedi
- Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Qasem Asgari
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Fatemeh Badakhshan
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Amirhossein Sakhteman
- Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Sara Ranjbar
- Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
| | - Mehdi Khoshneviszadeh
- Department of Medicinal Chemistry, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
- Medicinal and Natural Products Chemistry Research Center, Shiraz University of Medical Sciences, Shiraz, I.R. Iran
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Wang J, Ye X, Yang X, Cai Y, Wang S, Tang J, Sachdeva M, Qian Y, Hu W, Leeds JA, Yuan Y. Discovery of Novel Antibiotics as Covalent Inhibitors of Fatty Acid Synthesis. ACS Chem Biol 2020; 15:1826-1834. [PMID: 32568510 DOI: 10.1021/acschembio.9b00982] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The steady increase in the prevalence of multidrug-resistant Staphylococcus aureus has made the search for novel antibiotics to combat this clinically important pathogen an urgent matter. In an effort to discover antibacterials with new chemical structures and mechanisms, we performed a growth inhibition screen of a synthetic library against S. aureus and discovered a promising scaffold with a 1,3,5-oxadiazin-2-one core. These compounds are potent against both methicillin-sensitive and methicillin-resistant S. aureus strains. Isolation of compound-resistant strains followed by whole genome sequencing revealed its cellular target as FabH, a key enzyme in bacterial fatty acid synthesis. Detailed mechanism of action studies suggested the compounds inhibit FabH activity by covalently modifying its active site cysteine residue with high selectivity. A crystal structure of FabH protein modified by a selected compound Oxa1 further confirmed covalency and suggested a possible mechanism for reaction. Moreover, the structural snapshot provided an explanation for compound selectivity. On the basis of the structure, we designed and synthesized Oxa1 derivatives and evaluated their antibacterial activity. The structure-activity relationship supports the hypothesis that noncovalent recognition between compounds and FabH is critical for the activity of these covalent inhibitors. We believe further optimization of the current scaffold could lead to an antibacterial with potential to treat drug-resistant bacteria in the clinic.
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Affiliation(s)
- Jia Wang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xiaoping Ye
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xiaohan Yang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Youyan Cai
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Shengjun Wang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jieyu Tang
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Meena Sachdeva
- Novartis Institutes for Biomedical Research, Inc., Infectious Diseases Area, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Yu Qian
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Wenhao Hu
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jennifer A. Leeds
- Novartis Institutes for Biomedical Research, Inc., Infectious Diseases Area, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Yanqiu Yuan
- School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Drug Non-Clinical Evaluation and Research, Guangzhou 510990, China
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Exogenous Fatty Acids Remodel Staphylococcus aureus Lipid Composition through Fatty Acid Kinase. J Bacteriol 2020; 202:JB.00128-20. [PMID: 32366591 DOI: 10.1128/jb.00128-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/29/2020] [Indexed: 12/30/2022] Open
Abstract
Staphylococcus aureus can utilize exogenous fatty acids for phospholipid synthesis. The fatty acid kinase FakA is essential for this utilization by phosphorylating exogenous fatty acids for incorporation into lipids. How FakA impacts the lipid membrane composition is unknown. In this study, we used mass spectrometry to determine the membrane lipid composition and properties of S. aureus in the absence of fakA We found the fakA mutant to have increased abundance of lipids containing longer acyl chains. Since S. aureus does not synthesize unsaturated fatty acids, we utilized oleic acid (18:1) to track exogenous fatty acid incorporation into lipids. We observed a concentration-dependent incorporation of exogenous fatty acids into the membrane that required FakA. We also tested how FakA and exogenous fatty acids impact membrane-related physiology and identified changes in membrane potential, cellular respiration, and membrane fluidity. To mimic the host environment, we characterized the lipid composition of wild-type and fakA mutant bacteria grown in mouse skin homogenate. We show that wild-type S. aureus can incorporate exogenous unsaturated fatty acids from host tissue, highlighting the importance of FakA in the presence of host skin tissue. In conclusion, FakA is important for maintaining the composition and properties of the phospholipid membrane in the presence of exogenous fatty acids, impacting overall cell physiology.IMPORTANCE Environmental fatty acids can be harvested to supplement endogenous fatty acid synthesis to produce membranes and circumvent fatty acid biosynthesis inhibitors. However, how the inability to use these fatty acids impacts lipids is unclear. Our results reveal lipid composition changes in response to fatty acid addition and when S. aureus is unable to activate fatty acids through FakA. We identify concentration-dependent utilization of oleic acid that, when combined with previous work, provides evidence that fatty acids can serve as a signal to S. aureus Furthermore, using mouse skin homogenates as a surrogate for in vivo conditions, we showed that S. aureus can incorporate host fatty acids. This study highlights how exogenous fatty acids impact bacterial membrane composition and function.
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Lipidomic and Ultrastructural Characterization of the Cell Envelope of Staphylococcus aureus Grown in the Presence of Human Serum. mSphere 2020; 5:5/3/e00339-20. [PMID: 32554713 PMCID: PMC7300354 DOI: 10.1128/msphere.00339-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Comprehensive lipidomics of S. aureus grown in the presence of human serum suggests that human serum lipids can associate with the cell envelope without being truly integrated into the lipid membrane. However, fatty acids derived from human serum lipids, including unsaturated fatty acids, can be incorporated into lipid classes that can be biosynthesized by S. aureus itself. Cholesteryl esters and triglycerides are found to be the major source of incorporated fatty acids upon hydrolysis by lipases. These findings have significant implications for the nature of the S. aureus cell surface when grown in vivo. Changes in phospholipid and glycolipid abundances and fatty acid composition could affect membrane biophysics and function and the activity of membrane-targeting antimicrobials. Finally, the association of serum lipids with the cell envelope has implications for the physicochemical nature of the cell surface and its interaction with host defense systems. Staphylococcus aureus can incorporate exogenous straight-chain unsaturated and saturated fatty acids (SCUFAs and SCFAs, respectively) to replace some of the normally biosynthesized branched-chain fatty acids and SCFAs. In this study, the impact of human serum on the S. aureus lipidome and cell envelope structure was comprehensively characterized. When S. aureus was grown in the presence of 20% human serum, typical human serum lipids, such as cholesterol, sphingomyelin, phosphatidylethanolamines, and phosphatidylcholines, were present in the total lipid extracts. Mass spectrometry showed that SCUFAs were incorporated into all major S. aureus lipid classes, i.e., phosphatidylglycerols, lysyl-phosphatidylglycerols, cardiolipins, and diglucosyldiacylglycerols. Heat-killed S. aureus retained fewer serum lipids and failed to incorporate SCUFAs, suggesting that association and incorporation of serum lipids with S. aureus require a living or nondenatured cell. Cytoplasmic membranes isolated from lysostaphin-produced protoplasts of serum-grown cells retained serum lipids, but washing cells with Triton X-100 removed most of them. Furthermore, electron microscopy studies showed that serum-grown cells had thicker cell envelopes and associated material on the surface, which was partially removed by Triton X-100 washing. To investigate which serum lipids were preferentially hydrolyzed by S. aureus lipases for incorporation, we incubated individual serum lipid classes with S. aureus and found that cholesteryl esters (CEs) and triglycerides (TGs) are the major donors of the incorporated fatty acids. Further experiments using purified Geh lipase confirmed that CEs and TGs were the substrates of this enzyme. Thus, growth in the presence of serum altered the nature of the cell surface with implications for interactions with the host. IMPORTANCE Comprehensive lipidomics of S. aureus grown in the presence of human serum suggests that human serum lipids can associate with the cell envelope without being truly integrated into the lipid membrane. However, fatty acids derived from human serum lipids, including unsaturated fatty acids, can be incorporated into lipid classes that can be biosynthesized by S. aureus itself. Cholesteryl esters and triglycerides are found to be the major source of incorporated fatty acids upon hydrolysis by lipases. These findings have significant implications for the nature of the S. aureus cell surface when grown in vivo. Changes in phospholipid and glycolipid abundances and fatty acid composition could affect membrane biophysics and function and the activity of membrane-targeting antimicrobials. Finally, the association of serum lipids with the cell envelope has implications for the physicochemical nature of the cell surface and its interaction with host defense systems.
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Johnson ME, Fung LWM. Structural approaches to pathway-specific antimicrobial agents. Transl Res 2020; 220:114-121. [PMID: 32105648 PMCID: PMC7293926 DOI: 10.1016/j.trsl.2020.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 10/25/2022]
Abstract
This perspective provides an overview of the evolution of antibiotic discovery from a largely phenotypic-based effort, through an intensive structure-based design focus, to a more holistic approach today. The current focus on antibiotic development incorporates assay and discovery conditions that replicate the host environment as much as feasible. They also incorporate several strategies, including target identification and validation within the whole cell environment, a variety of target deconvolution methods, and continued refinement of structure-based design approaches.
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Affiliation(s)
- Michael E Johnson
- Department of Pharmaceutical Sciences, Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, Illinois.
| | - Leslie W-M Fung
- Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois.
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46
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Larson EC, Lim AL, Pond CD, Craft M, Čavužić M, Waldrop GL, Schmidt EW, Barrows LR. Pyrrolocin C and equisetin inhibit bacterial acetyl-CoA carboxylase. PLoS One 2020; 15:e0233485. [PMID: 32470050 PMCID: PMC7259786 DOI: 10.1371/journal.pone.0233485] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 05/06/2020] [Indexed: 11/25/2022] Open
Abstract
Antimicrobial resistance is a growing global health and economic concern. Current antimicrobial agents are becoming less effective against common bacterial infections. We previously identified pyrrolocins A and C, which showed activity against a variety of Gram-positive bacteria. Structurally similar compounds, known as pyrrolidinediones (e.g., TA-289, equisetin), also display antibacterial activity. However, the mechanism of action of these compounds against bacteria was undetermined. Here, we show that pyrrolocin C and equisetin inhibit bacterial acetyl-CoA carboxylase (ACC), the first step in fatty acid synthesis. We used transcriptomic data, metabolomic analysis, fatty acid rescue and acetate incorporation experiments to show that a major mechanism of action of the pyrrolidinediones is inhibition of fatty acid biosynthesis, identifying ACC as the probable molecular target. This hypothesis was further supported using purified proteins, demonstrating that biotin carboxylase is the inhibited component of ACC. There are few known antibiotics that target this pathway and, therefore, we believe that these compounds may provide the basis for alternatives to current antimicrobial therapy.
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Affiliation(s)
- Erica C. Larson
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, United States of America
| | - Albebson L. Lim
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, United States of America
| | - Christopher D. Pond
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, United States of America
| | - Matthew Craft
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Mirela Čavužić
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Grover L. Waldrop
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Eric W. Schmidt
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, United States of America
| | - Louis R. Barrows
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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47
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Radka CD, Frank MW, Yao J, Seetharaman J, Miller DJ, Rock CO. The genome of a Bacteroidetes inhabitant of the human gut encodes a structurally distinct enoyl-acyl carrier protein reductase (FabI). J Biol Chem 2020; 295:7635-7652. [PMID: 32317282 PMCID: PMC7261799 DOI: 10.1074/jbc.ra120.013336] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 04/20/2020] [Indexed: 01/07/2023] Open
Abstract
Enoyl-acyl carrier protein reductase (FabI) catalyzes a rate-controlling step in bacterial fatty-acid synthesis and is a target for antibacterial drug development. A phylogenetic analysis shows that FabIs fall into four divergent clades. Members of clades 1-3 have been structurally and biochemically characterized, but the fourth clade, found in members of phylum Bacteroidetes, is uncharacterized. Here, we identified the unique structure and conformational changes that distinguish clade 4 FabIs. Alistipes finegoldii is a prototypical Bacteroidetes inhabitant of the gut microbiome. We found that A. finegoldii FabI (AfFabI) displays cooperative kinetics and uses NADH as a cofactor, and its crystal structure at 1.72 Å resolution showed that it adopts a Rossmann fold as do other characterized FabIs. It also disclosed a carboxyl-terminal extension that forms a helix-helix interaction that links the protomers as a unique feature of AfFabI. An AfFabI·NADH crystal structure at 1.86 Å resolution revealed that this feature undergoes a large conformational change to participate in covering the NADH-binding pocket and establishing the water channels that connect the active site to the central water well. Progressive deletion of these interactions led to catalytically compromised proteins that fail to bind NADH. This unique conformational change imparted a distinct shape to the AfFabI active site that renders it refractory to a FabI drug that targets clade 1 and 3 pathogens. We conclude that the clade 4 FabI, found in the Bacteroidetes inhabitants of the gut, have several structural features and conformational transitions that distinguish them from other bacterial FabIs.
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Affiliation(s)
- Christopher D. Radka
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Matthew W. Frank
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Jiangwei Yao
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Jayaraman Seetharaman
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Darcie J. Miller
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105
| | - Charles O. Rock
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, To whom correspondence should be addressed:
262 Danny Thomas Place, Memphis, TN 38105. Tel.:
901-595-3491; E-mail:
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48
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Frank MW, Yao J, Batte JL, Gullett JM, Subramanian C, Rosch JW, Rock CO. Host Fatty Acid Utilization by Staphylococcus aureus at the Infection Site. mBio 2020; 11:e00920-20. [PMID: 32430471 PMCID: PMC7240157 DOI: 10.1128/mbio.00920-20] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 04/20/2020] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus utilizes the fatty acid (FA) kinase system to activate exogenous FAs for membrane synthesis. We developed a lipidomics workflow to determine the membrane phosphatidylglycerol (PG) molecular species synthesized by S. aureus at the thigh infection site. Wild-type S. aureus utilizes both host palmitate and oleate to acylate the 1 position of PG, and the 2 position is occupied by pentadecanoic acid arising from de novo biosynthesis. Inactivation of FakB2 eliminates the ability to assimilate oleate and inactivation of FakB1 reduces the content of saturated FAs and enhances oleate utilization. Elimination of FA activation in either ΔfakA or ΔfakB1 ΔfakB2 mutants does not impact growth. All S. aureus strains recovered from the thigh have significantly reduced branched-chain FAs and increased even-chain FAs compared to that with growth in rich laboratory medium. The molecular species pattern observed in the thigh was reproduced in the laboratory by growth in isoleucine-deficient medium containing exogenous FAs. S. aureus utilizes specific host FAs for membrane biosynthesis but also requires de novo FA biosynthesis initiated by isoleucine (or leucine) to produce pentadecanoic acid.IMPORTANCE The shortage of antibiotics against drug-resistant Staphylococcus aureus has led to the development of new drugs targeting the elongation cycle of fatty acid (FA) synthesis that are progressing toward the clinic. An objection to the use of FA synthesis inhibitors is that S. aureus can utilize exogenous FAs to construct its membrane, suggesting that the bacterium would bypass these therapeutics by utilizing host FAs instead. We developed a mass spectrometry workflow to determine the composition of the S. aureus membrane at the infection site to directly address how S. aureus uses host FAs. S. aureus strains that cannot acquire host FAs are as effective in establishing an infection as the wild type, but strains that require the utilization of host FAs for growth were attenuated in the mouse thigh infection model. We find that S. aureus does utilize host FAs to construct its membrane, but host FAs do not replace the requirement for pentadecanoic acid, a branched-chain FA derived from isoleucine (or leucine) that predominantly occupies the 2 position of S. aureus phospholipids. The membrane phospholipid structure of S. aureus mutants that cannot utilize host FAs indicates the isoleucine is a scarce resource at the infection site. This reliance on the de novo synthesis of predominantly pentadecanoic acid that cannot be obtained from the host is one reason why drugs that target fatty acid synthesis are effective in treating S. aureus infections.
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Affiliation(s)
- Matthew W Frank
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jiangwei Yao
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Justin L Batte
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jessica M Gullett
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Chitra Subramanian
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Jason W Rosch
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Charles O Rock
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, Tennessee, USA
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49
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Tiwari KB, Gatto C, Wilkinson BJ. Plasticity of Coagulase-Negative Staphylococcal Membrane Fatty Acid Composition and Implications for Responses to Antimicrobial Agents. Antibiotics (Basel) 2020; 9:E214. [PMID: 32354049 PMCID: PMC7277709 DOI: 10.3390/antibiotics9050214] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/18/2020] [Accepted: 04/27/2020] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus demonstrates considerable membrane lipid plasticity in response to different growth environments, which is of potential relevance to response and resistance to various antimicrobial agents. This information is not available for various species of coagulase-negative staphylococci, which are common skin inhabitants, can be significant human pathogens, and are resistant to multiple antibiotics. We determined the total fatty acid compositions of Staphylococcus auricularis, Staphylococcus capitis, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus saprophyticus, and Staphylococcus aureus for comparison purposes. Different proportions of branched-chain and straight-chain fatty acids were observed amongst the different species. However, growth in cation-supplemented Mueller-Hinton broth significantly increased the proportion of branched-chain fatty acids, and membrane fluidities as measured by fluorescence anisotropy. Cation-supplemented Mueller-Hinton broth is used for routine determination of antimicrobial susceptibilities. Growth in serum led to significant increases in straight-chain unsaturated fatty acids in the total fatty acid profiles, and decreases in branched-chain fatty acids. This indicates preformed fatty acids can replace biosynthesized fatty acids in the glycerolipids of coagulase-negative staphylococci, and indicates that bacterial fatty acid biosynthesis system II may not be a good target for antimicrobial agents in these organisms. Even though the different species are expected to be exposed to skin antimicrobial fatty acids, they were susceptible to the major skin antimicrobial fatty acid sapienic acid (C16:1Δ6). Certain species were not susceptible to linoleic acid (C18:2Δ9,12), but no obvious relationship to fatty acid composition could be discerned.
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Affiliation(s)
| | - Craig Gatto
- School of Biological Sciences, Illinois State University, Normal, IL 61761, USA
| | - Brian J. Wilkinson
- School of Biological Sciences, Illinois State University, Normal, IL 61761, USA
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50
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Schurig-Briccio LA, Parraga Solorzano PK, Lencina AM, Radin JN, Chen GY, Sauer JD, Kehl-Fie TE, Gennis RB. Role of respiratory NADH oxidation in the regulation of Staphylococcus aureus virulence. EMBO Rep 2020; 21:e45832. [PMID: 32202364 DOI: 10.15252/embr.201845832] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 02/21/2020] [Accepted: 02/26/2020] [Indexed: 01/28/2023] Open
Abstract
The success of Staphylococcus aureus as a pathogen is due to its capability of fine-tuning its cellular physiology to meet the challenges presented by diverse environments, which allows it to colonize multiple niches within a single vertebrate host. Elucidating the roles of energy-yielding metabolic pathways could uncover attractive therapeutic strategies and targets. In this work, we seek to determine the effects of disabling NADH-dependent aerobic respiration on the physiology of S. aureus. Differing from many pathogens, S. aureus has two type-2 respiratory NADH dehydrogenases (NDH-2s) but lacks the respiratory ion-pumping NDHs. Here, we show that the NDH-2s, individually or together, are not essential either for respiration or growth. Nevertheless, their absence eliminates biofilm formation, production of α-toxin, and reduces the ability to colonize specific organs in a mouse model of systemic infection. Moreover, we demonstrate that the reason behind these phenotypes is the alteration of the fatty acid metabolism. Importantly, the SaeRS two-component system, which responds to fatty acids regulation, is responsible for the link between NADH-dependent respiration and virulence in S. aureus.
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Affiliation(s)
| | - Paola K Parraga Solorzano
- Department of Microbiology, University of Illinois, Urbana, IL, USA.,Departamento de Ciencias de la Vida, Universidad de las Fuerzas Armada ESPE, Sangolquí, Ecuador
| | - Andrea M Lencina
- Department of Biochemistry, University of Illinois, Urbana, IL, USA
| | - Jana N Radin
- Department of Microbiology, University of Illinois, Urbana, IL, USA
| | - Grischa Y Chen
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - John-Demian Sauer
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Thomas E Kehl-Fie
- Department of Microbiology, University of Illinois, Urbana, IL, USA.,Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | - Robert B Gennis
- Department of Biochemistry, University of Illinois, Urbana, IL, USA
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