1
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Lin H, Xing J, Wang H, Wang S, Fang R, Li X, Li Z, Song N. Roles of Lipolytic enzymes in Mycobacterium tuberculosis pathogenesis. Front Microbiol 2024; 15:1329715. [PMID: 38357346 PMCID: PMC10865251 DOI: 10.3389/fmicb.2024.1329715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 01/10/2024] [Indexed: 02/16/2024] Open
Abstract
Mycobacterium tuberculosis (Mtb) is a bacterial pathogen that can endure for long periods in an infected patient, without causing disease. There are a number of virulence factors that increase its ability to invade the host. One of these factors is lipolytic enzymes, which play an important role in the pathogenic mechanism of Mtb. Bacterial lipolytic enzymes hydrolyze lipids in host cells, thereby releasing free fatty acids that are used as energy sources and building blocks for the synthesis of cell envelopes, in addition to regulating host immune responses. This review summarizes the relevant recent studies that used in vitro and in vivo models of infection, with particular emphasis on the virulence profile of lipolytic enzymes in Mtb. A better understanding of these enzymes will aid the development of new treatment strategies for TB. The recent work done that explored mycobacterial lipolytic enzymes and their involvement in virulence and pathogenicity was highlighted in this study. Lipolytic enzymes are expected to control Mtb and other intracellular pathogenic bacteria by targeting lipid metabolism. They are also potential candidates for the development of novel therapeutic agents.
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Affiliation(s)
- Hong Lin
- Weifang Key Laboratory of Respiratory Tract Pathogens and Drug Therapy, School of Life Science and Technology, Shandong Second Medical University, Weifang, China
| | - Jiayin Xing
- Weifang Key Laboratory of Respiratory Tract Pathogens and Drug Therapy, School of Life Science and Technology, Shandong Second Medical University, Weifang, China
| | - Hui Wang
- Weifang Key Laboratory of Respiratory Tract Pathogens and Drug Therapy, School of Life Science and Technology, Shandong Second Medical University, Weifang, China
| | - Shuxian Wang
- Weifang Key Laboratory of Respiratory Tract Pathogens and Drug Therapy, School of Life Science and Technology, Shandong Second Medical University, Weifang, China
| | - Ren Fang
- Weifang Key Laboratory of Respiratory Tract Pathogens and Drug Therapy, School of Life Science and Technology, Shandong Second Medical University, Weifang, China
| | - Xiaotian Li
- Weifang Key Laboratory of Respiratory Tract Pathogens and Drug Therapy, School of Life Science and Technology, Shandong Second Medical University, Weifang, China
| | - Zhaoli Li
- SAFE Pharmaceutical Technology Co. Ltd., Beijing, China
| | - Ningning Song
- Weifang Key Laboratory of Respiratory Tract Pathogens and Drug Therapy, School of Life Science and Technology, Shandong Second Medical University, Weifang, China
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2
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Ragavendran PV, Tripathi V, Gandotra S. Structure prediction-based insights into the patatin family of Mycobacterium tuberculosis. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36748562 DOI: 10.1099/mic.0.001270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Despite its genome sequencing more than two decades ago, the majority of the genes of Mycobacterium tuberculosis remain functionally uncharacterized. Patatins are one such class of proteins that, despite undergoing an expansion in this pathogenic species compared to their non-pathogenic cousins, remain largely unstudied. Recent advances in protein structure prediction using machine learning tools such as AlphaFold2 have provided high-confidence predicted structures for all M. tuberculosis proteins. Here we present detailed analyses of the patatin family of M. tuberculosis using AlphaFold-predicted structures, providing insights into likely modes of regulation, membrane interaction and substrate binding. Regulatory domains within this family of proteins include cyclic nucleotide binding, lid-like domains and other helical domains. Using structural homologues, we identified the likely membrane localization mechanisms and substrate-binding sites. These analyses reveal diversity in their regulatory capacity, mechanisms of membrane binding and likely length of fatty acid substrates. Together, this analysis suggests unique roles for the eight predicted patatins of M. tuberculosis.
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Affiliation(s)
- P V Ragavendran
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh- 201 002, India.,Immunology and Infectious Disease, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India, New Delhi, India
| | - Vaishnavi Tripathi
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh- 201 002, India.,Immunology and Infectious Disease, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India, New Delhi, India
| | - Sheetal Gandotra
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, Uttar Pradesh- 201 002, India.,Immunology and Infectious Disease, CSIR-Institute of Genomics and Integrative Biology, New Delhi, India, New Delhi, India
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3
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Li M, Patel HV, Cognetta AB, Smith TC, Mallick I, Cavalier JF, Previti ML, Canaan S, Aldridge BB, Cravatt BF, Seeliger JC. Identification of cell wall synthesis inhibitors active against Mycobacterium tuberculosis by competitive activity-based protein profiling. Cell Chem Biol 2022; 29:883-896.e5. [PMID: 34599873 PMCID: PMC8964833 DOI: 10.1016/j.chembiol.2021.09.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/08/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022]
Abstract
The identification and validation of a small molecule's targets is a major bottleneck in the discovery process for tuberculosis antibiotics. Activity-based protein profiling (ABPP) is an efficient tool for determining a small molecule's targets within complex proteomes. However, how target inhibition relates to biological activity is often left unexplored. Here, we study the effects of 1,2,3-triazole ureas on Mycobacterium tuberculosis (Mtb). After screening ∼200 compounds, we focus on 4 compounds that form a structure-activity series. The compound with negligible activity reveals targets, the inhibition of which is functionally less relevant for Mtb growth and viability, an aspect not addressed in other ABPP studies. Biochemistry, computational docking, and morphological analysis confirms that active compounds preferentially inhibit serine hydrolases with cell wall and lipid metabolism functions and that disruption of the cell wall underlies biological activity. Our findings show that ABPP identifies the targets most likely relevant to a compound's antibacterial activity.
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Affiliation(s)
- Michael Li
- Department of Pharmacological Sciences and Immunology Stony Brook University, Stony Brook, NY 11790, USA
| | - Hiren V Patel
- Department of Microbiology and Immunology Stony Brook University, Stony Brook, NY 11790, USA
| | - Armand B Cognetta
- Department of Chemistry, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Trever C Smith
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA
| | - Ivy Mallick
- Aix-Marseille Université, CNRS, LISM, IMM FR3479, 13402 Marseille, France
| | | | - Mary L Previti
- Department of Pharmacological Sciences and Immunology Stony Brook University, Stony Brook, NY 11790, USA
| | - Stéphane Canaan
- Aix-Marseille Université, CNRS, LISM, IMM FR3479, 13402 Marseille, France
| | - Bree B Aldridge
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA 02111, USA
| | - Benjamin F Cravatt
- Department of Chemistry, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jessica C Seeliger
- Department of Pharmacological Sciences and Immunology Stony Brook University, Stony Brook, NY 11790, USA.
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4
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Wei J, Fei Z, Pan G, Weiss LM, Zhou Z. Current Therapy and Therapeutic Targets for Microsporidiosis. Front Microbiol 2022; 13:835390. [PMID: 35356517 PMCID: PMC8959712 DOI: 10.3389/fmicb.2022.835390] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/14/2022] [Indexed: 11/13/2022] Open
Abstract
Microsporidia are obligate intracellular, spore-forming parasitic fungi which are grouped with the Cryptomycota. They are both opportunistic pathogens in humans and emerging veterinary pathogens. In humans, they cause chronic diarrhea in immune-compromised patients and infection is associated with increased mortality. Besides their role in pébrine in sericulture, which was described in 1865, the prevalence and severity of microsporidiosis in beekeeping and aquaculture has increased markedly in recent decades. Therapy for these pathogens in medicine, veterinary, and agriculture has become a recent focus of attention. Currently, there are only a few commercially available antimicrosporidial drugs. New therapeutic agents are needed for these infections and this is an active area of investigation. In this article we provide a comprehensive summary of the current as well as several promising new agents for the treatment of microsporidiosis including: albendazole, fumagillin, nikkomycin, orlistat, synthetic polyamines, and quinolones. Therapeutic targets which could be utilized for the design of new drugs are also discussed including: tubulin, type 2 methionine aminopeptidase, polyamines, chitin synthases, topoisomerase IV, triosephosphate isomerase, and lipase. We also summarize reports on the utility of complementary and alternative medicine strategies including herbal extracts, propolis, and probiotics. This review should help facilitate drug development for combating microsporidiosis.
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Affiliation(s)
- Junhong Wei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Zhihui Fei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Guoqing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY, United States
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Zeyang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Microsporidia Infection and Control, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
- College of Life Sciences, Chongqing Normal University, Chongqing, China
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5
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Khan SS, Sudasinghe TD, Landgraf AD, Ronning DR, Sucheck SJ. Total Synthesis of Tetrahydrolipstatin, Its Derivatives, and Evaluation of Their Ability to Potentiate Multiple Antibiotic Classes against Mycobacterium Species. ACS Infect Dis 2021; 7:2876-2888. [PMID: 34478259 PMCID: PMC8630808 DOI: 10.1021/acsinfecdis.1c00283] [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] [Indexed: 11/29/2022]
Abstract
Tetrahydrolipstatin (THL, 1a) has been shown to inhibit both mammalian and bacterial α/β hydrolases. In the case of bacterial systems, THL is a known inhibitor of several Mycobacterium tuberculosis hydrolases involved in mycomembrane biosynthesis. Herein we report a highly efficient eight-step asymmetric synthesis of THL using a route that allows modification of the THL α-chain substituent to afford compounds 1a through 1e. The key transformation in the synthesis was use of a (TPP)CrCl/Co2(CO)8-catalyzed regioselective and stereospecific carbonylation on an advanced epoxide intermediate to yield a trans-β-lactone. These compounds are modest inhibitors of Ag85A and Ag85C, two α/β hydrolases of M. tuberculosis involved in the biosynthesis of the mycomembrane. Among these compounds, 10d showed the highest inhibitory effect on Ag85A (34 ± 22 μM) and Ag85C (66 ± 8 μM), and its X-ray structure was solved in complex with Ag85C to 2.5 Å resolution. In contrast, compound 1e exhibited the best-in-class MICs of 50 μM (25 μg/mL) and 16 μM (8.4 μg/mL) against M. smegmatis and M. tuberculosis H37Ra, respectively, using a microtiter assay plate. Combination of 1e with 13 well-established antibiotics synergistically enhanced the potency of few of these antibiotics in M. smegmatis and M. tuberculosis H37Ra. Compound 1e applied at concentrations 4-fold lower than its MIC enhanced the MIC of the synergistic antibiotic by 2-256-fold. In addition to observing synergy with first-line drugs, rifamycin and isoniazid, the MIC of vancomycin against M. tuberculosis H37Ra was 65 μg/mL; however, the MIC was lowered to 0.25 μg/mL in the presence of 2.1 μg/mL 1e demonstrating the potential of targeting mycobacterial hydrolases involved in mycomembrane and peptidoglycan biosynthesis.
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Affiliation(s)
- Saniya S Khan
- Department of Chemistry & Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Thanuja D Sudasinghe
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Alexander D Landgraf
- Department of Chemistry & Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Donald R Ronning
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Steven J Sucheck
- Department of Chemistry & Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
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6
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Cavalier JF, Spilling CD, Durand T, Camoin L, Canaan S. Lipolytic enzymes inhibitors: A new way for antibacterial drugs discovery. Eur J Med Chem 2020; 209:112908. [PMID: 33071055 DOI: 10.1016/j.ejmech.2020.112908] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 09/29/2020] [Accepted: 10/03/2020] [Indexed: 10/23/2022]
Abstract
Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tb) still remains the deadliest infectious disease worldwide with 1.5 million deaths in 2018, of which about 15% are attributed to resistant strains. Another significant example is Mycobacterium abscessus (M. abscessus), a nontuberculous mycobacteria (NTM) responsible for cutaneous and pulmonary infections, representing up to 95% of NTM infections in cystic fibrosis (CF) patients. M. abscessus is a new clinically relevant pathogen and is considered one of the most drug-resistant mycobacteria for which standardized chemotherapeutic regimens are still lacking. Together the emergence of M. tb and M. abscessus multi-drug resistant strains with ineffective and expensive therapeutics, have paved the way to the development of new classes of anti-mycobacterial agents offering additional therapeutic options. In this context, specific inhibitors of mycobacterial lipolytic enzymes represent novel and promising antibacterial molecules to address this challenging issue. The results highlighted here include a complete overview of the antibacterial activities, either in broth medium or inside infected macrophages, of two families of promising and potent anti-mycobacterial multi-target agents, i.e. oxadiazolone-core compounds (OX) and Cyclophostin & Cyclipostins analogs (CyC); the identification and biochemical validation of their effective targets (e.g., the antigen 85 complex and TesA playing key roles in mycolic acid metabolism) together with their respective crystal structures. To our knowledge, these are the first families of compounds able to target and impair replicating as well as intracellular bacteria. We are still impelled in deciphering their mode of action and finding new potential therapeutic targets against mycobacterial-related diseases.
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Affiliation(s)
- Jean-François Cavalier
- Aix-Marseille Univ., CNRS, LISM, Institut de Microbiologie de La Méditerranée FR3479, Marseille, France.
| | - Christopher D Spilling
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, One University Boulevard, St. Louis, Missouri, 63121, United States
| | - Thierry Durand
- IBMM, Univ Montpellier, CNRS, ENSCM, Montpellier, France
| | - Luc Camoin
- Aix-Marseille Univ., INSERM, CNRS, Institut Paoli-Calmettes, CRCM, Marseille Protéomique, Marseille, France
| | - Stéphane Canaan
- Aix-Marseille Univ., CNRS, LISM, Institut de Microbiologie de La Méditerranée FR3479, Marseille, France.
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7
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Cui Z, Dang G, Song N, Cui Y, Li Z, Zang X, Liu H, Wang Z, Liu S. Rv3091, An Extracellular Patatin-Like Phospholipase in Mycobacterium tuberculosis, Prolongs Intracellular Survival of Recombinant Mycolicibacterium smegmatis by Mediating Phagosomal Escape. Front Microbiol 2020; 11:2204. [PMID: 33042041 PMCID: PMC7517356 DOI: 10.3389/fmicb.2020.532371] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 08/19/2020] [Indexed: 12/02/2022] Open
Abstract
Patatin-like phospholipases (PLPs) are important virulence factors of many pathogens. However, there are no prevailing studies regarding PLPs as a virulence factor of Mycobacterium tuberculosis (Mtb). Analysis of Rv3091, a putative protein of Mtb, shows that it belongs to the PLPs family. Here, we cloned and expressed the rv3091 gene in Mycobacterium smegmatis and, subsequently, conducted protein purification and characterization. We show that it possesses phospholipase A1, phospholipase A2, and lipase activity. We confirm the putative active site residues, namely, Ser214 and Asp407, using site directed mutagenesis. The Rv3091 is an extracellular protein that alters the colony morphology of M. smegmatis. The presence of Rv3091 enhances the intracellular survival capability of M. smegmatis in murine peritoneal macrophages. Additionally, it promotes M. smegmatis phagosomal escape from macrophages. Moreover, Rv3091 significantly increased the survival of M. smegmatis and aggravated lesions in C57BL/6 J murine lungs in vivo. Taken together, our results indicate that Rv3091 as an extracellular PLP that is critical to the pathogenicity of mycobacterium as it allows mycobacterium to utilize phospholipids for its growth and provides resistance to phagosome killing, resulting in its enhanced intracellular survival.
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Affiliation(s)
- Ziyin Cui
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Guanghui Dang
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ningning Song
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yingying Cui
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhe Li
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xinxin Zang
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Hongxiu Liu
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Zhongxing Wang
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
| | - Siguo Liu
- State Key Laboratory of Veterinary Biotechnology, Division of Bacterial Diseases, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China
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8
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Abou-El-Naga IF, Said DE, Gaafar MR, Ahmed SM, El-Deeb SA. A new scope for orlistat: Effect of approved anti-obesity drug against experimental microsporidiosis. Med Mycol 2019. [PMID: 29529254 DOI: 10.1093/mmy/myy005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
As the current therapies for intestinal microsporidiosis are either inconsistent in their efficacies or hampered by several adverse effects, alternative antimicrosporidial agents are being sought. The present study is the first that was designed to evaluate the potency of orlistat, an approved anti-obesity drug, against intestinal microsporidiosis caused by both Enterocytozoon bieneusi and Encephalitozoon intestinalis. Results were assessed through studying fecal and intestinal spore load, intestinal histopathological changes, viability, and infectivity of spores from treated animals. Results showed that orlistat has promising antimicrosporidia potential, with better results in E. intestinalis than E. bieneusi. The animals that received orlistat showed statistically significant decrease in the fecal and intestinal spore load, when compared to the corresponding control infected nontreated mice. The results were insignificant compared to fumagillin and albendazole. Light microscopic examination of stained intestinal sections revealed amelioration of the pathological changes and decreased inflammatory cells detected in the control infected nontreated mice. Spores encountered from stool of orlistat-treated E. bieneusi and E. intestinalis mice showed low viability and significant reduction of infectivity versus their control. Thus, considering the results of the present work, orlistat proved its effectiveness against the intestinal microsporidial infection.
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Affiliation(s)
| | - D E Said
- Department of Medical Parasitology
| | | | - S M Ahmed
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Alexandria University, Egypt
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9
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Kuskovsky R, Lloyd D, Arora K, Plotkin BJ, Green JM, Boshoff HI, Barry C, Deschamps J, Konaklieva MI. C4-Phenylthio β-lactams: Effect of the chirality of the β-lactam ring on antimicrobial activity. Bioorg Med Chem 2019; 27:115050. [PMID: 31474471 DOI: 10.1016/j.bmc.2019.115050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/16/2019] [Accepted: 08/15/2019] [Indexed: 01/02/2023]
Abstract
C4-phenylthio β-lactams are a new family of antibacterial agents that have activity against two phylogenetically distant bacteria - Mycobacterium tuberculosis (Mtb) and Moraxella catarrhalis (M. cat). These compounds are effective against β-lactamase producing Mtb and M. cat unlike the clinically relevant β-lactam antibiotics. The structure-activity relationship for the C4 phenylthio β-lactams has not yet been completely defined. Earlier efforts in our laboratories established that the C4-phenylthio substituent is essential for antimicrobial activity, while the N1 carbamyl substituent plays a more subtle role. In this present study, we investigated the role that the stereochemistry at C4 plays in these compounds' antibacterial activity. This was achieved by synthesizing and testing the antimicrobial activity of diastereomers with a chiral carbamyl group at N1. Our findings indicate that a strict stereochemistry for the C4-phenylthio β-lactams is not required to obtain optimal anti-Mtb and anti-M. cat activity. Furthermore, the structure-bioactivity profiles more closely relate to the electronic requirement of the phenylthiogroup. In addition, the MICs of Mtb are sensitive to growth medium composition. Select compounds showed activity against non-replicating and multi-drug resistant Mtb.
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Affiliation(s)
| | - Dina Lloyd
- Department of Chemistry, American University, Washington, DC 20016, USA
| | - Kriti Arora
- Tuberculosis Research Section, LCIM, NIAID, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Balbina J Plotkin
- Department of Microbiology and Immunology, Midwestern University, Chicago, IL 60515, USA
| | - Jacalyn M Green
- Department of Biochemistry, Midwestern University, Chicago, IL 60515, USA
| | - Helena I Boshoff
- Tuberculosis Research Section, LCIM, NIAID, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Clifton Barry
- Tuberculosis Research Section, LCIM, NIAID, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Jeffrey Deschamps
- Naval Research Laboratory, Code 6930 4555 Overlook Ave., Washington, DC 20375, USA
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10
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Yang D, Vandenbussche G, Vertommen D, Evrard D, Abskharon R, Cavalier JF, Berger G, Canaan S, Khan MS, Zeng S, Wohlkönig A, Prévost M, Soumillion P, Fontaine V. Methyl arachidonyl fluorophosphonate inhibits Mycobacterium tuberculosis thioesterase TesA and globally affects vancomycin susceptibility. FEBS Lett 2019; 594:79-93. [PMID: 31388991 DOI: 10.1002/1873-3468.13555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/18/2019] [Accepted: 07/25/2019] [Indexed: 11/11/2022]
Abstract
Phthiocerol dimycocerosates and phenolic glycolipids (PGL) are considered as major virulence elements of Mycobacterium tuberculosis, in particular because of their involvement in cell wall impermeability and drug resistance. The biosynthesis of these waxy lipids involves multiple enzymes, including thioesterase A (TesA). We observed that purified recombinant M. tuberculosis TesA is able to dimerize in the presence of palmitoyl-CoA and our 3D structure model of TesA with this acyl-CoA suggests hydrophobic interaction requirement for dimerization. Furthermore, we identified that methyl arachidonyl fluorophosphonate, which inhibits TesA by covalently modifying the catalytic serine, also displays a synergistic antimicrobial activity with vancomycin further warranting the development of TesA inhibitors as valuable antituberculous drug candidates.
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Affiliation(s)
- Dong Yang
- Microbiology, Bioorganic and Macromolecular Chemistry Unit, Faculty of Pharmacy, Université Libre de Bruxelles (ULB), Belgium
| | - Guy Vandenbussche
- Laboratory for the Structure and Function of Biological Membranes, Faculty of Sciences, Université Libre de Bruxelles (ULB), Belgium
| | - Didier Vertommen
- de Duve Institute, Université Catholique de Louvain (UCL), Brussels, Belgium
| | - Damien Evrard
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCL), Louvain-la-Neuve, Belgium
| | - Romany Abskharon
- National Institute of Oceanography and Fisheries (NIOF), Cairo, Egypt.,VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | | | - Gilles Berger
- Microbiology, Bioorganic and Macromolecular Chemistry Unit, Faculty of Pharmacy, Université Libre de Bruxelles (ULB), Belgium
| | | | - Mohammad Shahneawz Khan
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCL), Louvain-la-Neuve, Belgium
| | - Sheng Zeng
- Microbiology, Bioorganic and Macromolecular Chemistry Unit, Faculty of Pharmacy, Université Libre de Bruxelles (ULB), Belgium
| | - Alexandre Wohlkönig
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Martine Prévost
- Laboratory for the Structure and Function of Biological Membranes, Faculty of Sciences, Université Libre de Bruxelles (ULB), Belgium
| | - Patrice Soumillion
- Biochemistry and Genetics of Microorganisms, Louvain Institute of Biomolecular Science and Technology, Université Catholique de Louvain (UCL), Louvain-la-Neuve, Belgium
| | - Véronique Fontaine
- Microbiology, Bioorganic and Macromolecular Chemistry Unit, Faculty of Pharmacy, Université Libre de Bruxelles (ULB), Belgium
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11
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Vartak A, Goins C, de Moura VCN, Schreidah CM, Landgraf AD, Lin B, Du J, Jackson M, Ronning DR, Sucheck SJ. Biochemical and microbiological evaluation of N-aryl urea derivatives against mycobacteria and mycobacterial hydrolases. MEDCHEMCOMM 2019; 10:1197-1204. [PMID: 31741730 PMCID: PMC6677023 DOI: 10.1039/c9md00122k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/01/2019] [Indexed: 12/28/2022]
Abstract
A focused library of 24 N-aryl urea derivatives was prepared and evaluated against serine esterases of Mycobacterium tuberculosis (Mtb) Rv3802c and Mtb Ag85C. The members of the library were evaluated for both selectivity and mode of inhibition. Furan-based urea derivative 6c was found to be the most potent non-covalent inhibitor of Rv3802c with a K i value of 5.2 ± 0.7 μM. On the other hand, triazole-based ureas 10a and 10b selectively inhibited Ag85C irreversibly with a k inact/K i value of 2.3 ± 0.3 and 5.5 ± 0.4 × 10-3 μM-1 min-1, respectively. The library was also evaluated for minimum inhibitory concentration (MIC) against two strains of Mtb, Mycobacterium smegmatis, and Mycobacterium abscessus. Compounds 4a and 4c were active against Mtb H37Rv mc26206 with MIC values of 3.12 and 1.5 μM, respectively. Closely related 4e showed similar activity against Mtb H37Rv mc26206 but also possessed activity against Mtb H37Ra, Mycobacterium smegmatis and Mycobacterium abscessus. Compounds 4a, 4c, and 4e all contained a common 1-(cyclohexylmethyl)-3-phenylurea motif. In summary, we identified a selective non-covalent inhibitor of Rv3802c and covalently irreversible inhibitors of Ag85C as well as the 1-(cyclohexylmethyl)-3-phenylurea motif which showed activity against a variety of mycobacteria.
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Affiliation(s)
- Abhishek Vartak
- Department of Chemistry and Biochemistry , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , USA . ;
| | - Christopher Goins
- Center for Therapeutic Discovery , Lerner Research Institute , Cleveland Clinic Foundation , Cleveland , OH 44195 , USA
| | - Vinicius Calado Nogueira de Moura
- Mycobacteria Research Laboratories , Department of Microbiology , Immunology and Pathology , Colorado State University , Fort Collins , USA
| | - Celine M Schreidah
- Department of Chemistry and Biochemistry , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , USA . ;
| | - Alexander D Landgraf
- Department of Chemistry and Biochemistry , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , USA . ;
| | - Boren Lin
- Department of Biological Sciences , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , USA
| | - Jianyang Du
- Department of Biological Sciences , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , USA
| | - Mary Jackson
- Mycobacteria Research Laboratories , Department of Microbiology , Immunology and Pathology , Colorado State University , Fort Collins , USA
| | - Donald R Ronning
- Department of Chemistry and Biochemistry , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , USA . ;
| | - Steven J Sucheck
- Department of Chemistry and Biochemistry , University of Toledo , 2801 West Bancroft Street , Toledo , Ohio 43606 , USA . ;
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12
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LipG a bifunctional phospholipase/thioesterase involved in mycobacterial envelope remodeling. Biosci Rep 2018; 38:BSR20181953. [PMID: 30487163 PMCID: PMC6435540 DOI: 10.1042/bsr20181953] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/27/2018] [Accepted: 11/27/2018] [Indexed: 12/28/2022] Open
Abstract
Tuberculosis caused by Mycobacterium tuberculosis is currently one of the leading causes of death from an infectious agent. The main difficulties encountered in eradicating this bacteria are mainly related to (i) a very complex lipid composition of the bacillus cell wall, (ii) its ability to hide from the immune system inside the granulomas, and (iii) the increasing number of resistant strains. In this context, we were interested in the Rv0646c (lipGMTB ) gene located upstream to the mmaA cluster which is described as being crucial for the production of cell wall components and required for the bacilli adaptation and survival in mouse macrophages. Using biochemical experiments combined with the construction of deletion and overexpression mutant strains in Mycobacterium smegmatis, we found that LipGMTB is a cytoplasmic membrane-associated enzyme that displays both phospholipase and thioesterase activities. Overproduction of LipGMTB decreases the glycopeptidolipids (GPL) level concomitantly to an increase in phosphatidylinositol (PI) which is the precursor of the PI mannoside (PIM), an essential lipid component of the bacterial cell wall. Conversely, deletion of the lipGMS gene in M. smegmatis leads to an overproduction of GPL, and subsequently decreases the strain susceptibility to various antibiotics. All these findings demonstrate that LipG is involved in cell envelope biosynthesis/remodeling, and consequently this enzyme may thus play an important role in mycobacterial physiology.
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13
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Biochemical and Structural Characterization of TesA, a Major Thioesterase Required for Outer-Envelope Lipid Biosynthesis in Mycobacterium tuberculosis. J Mol Biol 2018; 430:5120-5136. [DOI: 10.1016/j.jmb.2018.09.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 09/11/2018] [Accepted: 09/24/2018] [Indexed: 01/25/2023]
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14
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Divya M B, Vemula M, Balakrishnan K, Banerjee S, Guruprasad L. Mycobacterium tuberculosis PE1 and PE2 proteins carrying conserved α/β-serine hydrolase domain are esterases hydrolyzing short to medium chain p-nitrophenyl esters. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 140:90-102. [DOI: 10.1016/j.pbiomolbio.2018.04.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/23/2018] [Accepted: 04/30/2018] [Indexed: 10/17/2022]
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15
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Rameshwaram NR, Singh P, Ghosh S, Mukhopadhyay S. Lipid metabolism and intracellular bacterial virulence: key to next-generation therapeutics. Future Microbiol 2018; 13:1301-1328. [DOI: 10.2217/fmb-2018-0013] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Lipid metabolism is thought to play a key role in the pathogenicity of several intracellular bacteria. Bacterial lipolytic enzymes hydrolyze lipids from the host cell to release free fatty acids which are used as an energy source and building blocks for the synthesis of cell envelope and also to modulate host immune responses. In this review, we discussed the role of lipid metabolism and lipolytic enzymes in the life cycle and virulence of Mycobacterium tuberculosis and other intracellular bacteria. The lipolytic enzymes appear to be potential candidates for developing novel therapeutics by targeting lipid metabolism for controlling M. tuberculosis and other intracellular pathogenic bacteria. [Formula: see text]
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Affiliation(s)
- Nagender Rao Rameshwaram
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting & Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad, India. 500 039
| | - Parul Singh
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting & Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad, India. 500 039
- Graduate Studies, Manipal University, Manipal, Karnataka, India. 576 104
| | - Sudip Ghosh
- Molecular Biology Division, National Institute of Nutrition (ICMR), Jamai-Osmania PO, Hyderabad, India. 500 007
| | - Sangita Mukhopadhyay
- Laboratory of Molecular Cell Biology, Centre for DNA Fingerprinting & Diagnostics (CDFD), Inner Ring Road, Uppal, Hyderabad, India. 500 039
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16
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Goins CM, Sudasinghe TD, Liu X, Wang Y, O'Doherty GA, Ronning DR. Characterization of Tetrahydrolipstatin and Stereoderivatives on the Inhibition of Essential Mycobacterium tuberculosis Lipid Esterases. Biochemistry 2018; 57:2383-2393. [PMID: 29601187 DOI: 10.1021/acs.biochem.8b00152] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Tetrahydrolipstatin (THL) is a covalent inhibitor of many serine esterases. In mycobacteria, THL has been found to covalently react with 261 lipid esterases upon treatment of Mycobacterium bovis cell lysate. However, the covalent adduct is considered unstable in some cases because of the hydrolysis of the enzyme-linked THL adduct resulting in catalytic turnover. In this study, a library of THL stereoderivatives was tested against three essential Mycobacterium tuberculosis lipid esterases of interest for drug development to assess how the stereochemistry of THL affects respective enzyme inhibition and allows for cross enzyme inhibition. The mycolyltransferase Antigen 85C (Ag85C) was found to be stereospecific with regard to THL; covalent inhibition occurs within minutes and was previously shown to be irreversible. Conversely, the Rv3802 phospholipase A/thioesterase was more accepting of a variety of THL configurations and uses these compounds as alternative substrates. The reaction of the THL stereoderivatives with the thioesterase domain of polyketide synthase 13 (Pks13-TE) also leads to hydrolytic turnover and is nonstereospecific but occurs on a slower, multihour time scale. Our findings suggest the stereochemistry of the β-lactone ring of THL is important for cross enzyme reactivity, while the two stereocenters of the peptidyl arm can affect enzyme specificity and the catalytic hydrolysis of the β-lactone ring. The observed kinetic data for all three target enzymes are supported by recently published X-ray crystal structures of Ag85C, Rv3802, and Pks13-TE. Insights from this study provide a molecular basis for the kinetic modulation of three essential M. tuberculosis lipid esterases by THL and can be applied to increase potency and enzyme residence times and enhance the specificity of the THL scaffold.
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Affiliation(s)
- Christopher M Goins
- Department of Chemistry and Biochemistry , University of Toledo , Toledo , Ohio 43606 , United States
| | - Thanuja D Sudasinghe
- Department of Chemistry and Biochemistry , University of Toledo , Toledo , Ohio 43606 , United States
| | - Xiaofan Liu
- Department of Chemistry and Chemical Biology , Northeastern University , Boston , Massachusetts 02115 , United States
| | - Yanping Wang
- Department of Chemistry and Chemical Biology , Northeastern University , Boston , Massachusetts 02115 , United States
| | - George A O'Doherty
- Department of Chemistry and Chemical Biology , Northeastern University , Boston , Massachusetts 02115 , United States
| | - Donald R Ronning
- Department of Chemistry and Biochemistry , University of Toledo , Toledo , Ohio 43606 , United States
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17
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Ravindran MS, Wenk MR. Activity-Based Lipid Esterase Profiling of M. bovis BCG at Different Metabolic States Using Tetrahydrolipstatin (THL) as Bait. Methods Mol Biol 2018; 1491:75-85. [PMID: 27778282 DOI: 10.1007/978-1-4939-6439-0_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
This chapter provides a step-by-step protocol using activity-based protein profiling (ABPP) as a chemical-proteomic tool to survey the antibiotic properties of a small molecule. Here, we investigate the molecular mechanism behind the bactericidal activity of tetrahydrolipstatin (THL). ABPP relies on small molecule probes that target the active site of specific enzymes in complex proteomes. These probes in turn are equipped with a reporter tag that allows capturing, visualization, enrichment, identification, and quantification of its targets either in vitro or in situ. THL possesses bactericidal activities, but its precise spectrum of molecular targets is poorly characterized. Here, we used THL analogs functionalized to enable Huisgen-base cycloaddition, commonly known as "click chemistry," to identify target proteins after enrichment from mycobacterial cell lysates obtained from different physiological conditions.
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Affiliation(s)
- Madhu Sudhan Ravindran
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (NUS), Singapore, 117456, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Markus R Wenk
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore (NUS), Singapore, 117456, Singapore. .,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore, 117456, Singapore. .,Department of Biological Sciences, National University of Singapore (NUS), Singapore, 117456, Singapore. .,Swiss Tropical and Public Health Institute, University of Basel, 4051, Basel, Switzerland.
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18
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Goins CM, Schreidah CM, Dajnowicz S, Ronning DR. Structural basis for lipid binding and mechanism of the Mycobacterium tuberculosis Rv3802 phospholipase. J Biol Chem 2017; 293:1363-1372. [PMID: 29247008 DOI: 10.1074/jbc.ra117.000240] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/05/2017] [Indexed: 11/06/2022] Open
Abstract
The Mycobacterium tuberculosis rv3802c gene encodes an essential enzyme with thioesterase and phospholipase A activity. Overexpression of Rv3802 orthologs in Mycobacterium smegmatis and Corynebacterium glutamicum increases mycolate content and decreases glycerophospholipids. Although a role in modulating the lipid composition of the unique mycomembrane has been proposed, the true biological function of Rv3802 remains uncertain. In this study, we present the first M. tuberculosis Rv3802 X-ray crystal structure, solved to 1.7 Å resolution. On the basis of the binding of PEG molecules to Rv3802, we identified its lipid-binding site and the structural basis for phosphatidyl-based substrate binding and phospholipase A activity. We found that movement of the α8-helix affords lipid binding and is required for catalytic turnover through covalent tethering. We gained insights into the mechanism of acyl hydrolysis by observing differing arrangements of PEG and water molecules within the active site. This study provides structural insights into biological function and facilitates future structure-based drug design toward Rv3802.
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Affiliation(s)
- Christopher M Goins
- From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390 and
| | - Celine M Schreidah
- From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390 and
| | - Steven Dajnowicz
- From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390 and.,the Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Donald R Ronning
- From the Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606-3390 and
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19
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Touchette MH, Van Vlack ER, Bai L, Kim J, Cognetta AB, Previti ML, Backus KM, Martin DW, Cravatt BF, Seeliger JC. A Screen for Protein-Protein Interactions in Live Mycobacteria Reveals a Functional Link between the Virulence-Associated Lipid Transporter LprG and the Mycolyltransferase Antigen 85A. ACS Infect Dis 2017; 3:336-348. [PMID: 28276676 DOI: 10.1021/acsinfecdis.6b00179] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Outer membrane lipids in pathogenic mycobacteria are important for virulence and survival. Although the biosynthesis of these lipids has been extensively studied, mechanisms responsible for their assembly in the outer membrane are not understood. In the study of Gram-negative outer membrane assembly, protein-protein interactions define transport mechanisms, but analogous interactions have not been explored in mycobacteria. Here we identified interactions with the lipid transport protein LprG. Using site-specific photo-cross-linking in live mycobacteria, we mapped three major interaction interfaces within LprG. We went on to identify proteins that cross-link at the entrance to the lipid binding pocket, an area likely relevant to LprG transport function. We verified LprG site-specific interactions with two hits, the conserved lipoproteins LppK and LppI. We further showed that LprG interacts physically and functionally with the mycolyltransferase Ag85A, as loss of either protein leads to similar defects in cell growth and mycolylation. Overall, our results support a model in which protein interactions coordinate multiple pathways in outer membrane biogenesis and connect lipid biosynthesis to transport.
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Affiliation(s)
- Megan H. Touchette
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Erik R. Van Vlack
- Department of Chemistry, Stony Brook University, Stony
Brook, New York 11790, United States
| | - Lu Bai
- Department of Chemistry, Stony Brook University, Stony
Brook, New York 11790, United States
| | - Jia Kim
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Armand B. Cognetta
- Department of Chemical Physiology, The
Skaggs Institute for Chemical Biology, The Scripps Research Institute, La
Jolla, California 92037, United States
| | - Mary L. Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Keriann M. Backus
- Department of Chemical Physiology, The
Skaggs Institute for Chemical Biology, The Scripps Research Institute, La
Jolla, California 92037, United States
| | - Dwight W. Martin
- Department of Medicine, Stony Brook University, Stony
Brook, New York 11794, United States
- Proteomics Center, Stony Brook University, Stony
Brook, New York 11794, United States
| | - Benjamin F. Cravatt
- Department of Chemical Physiology, The
Skaggs Institute for Chemical Biology, The Scripps Research Institute, La
Jolla, California 92037, United States
| | - Jessica C. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony
Brook, New York 11794, United States
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20
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Tallman KR, Levine SR, Beatty KE. Small-Molecule Probes Reveal Esterases with Persistent Activity in Dormant and Reactivating Mycobacterium tuberculosis. ACS Infect Dis 2016; 2:936-944. [PMID: 27690385 DOI: 10.1021/acsinfecdis.6b00135] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is the deadliest bacterial pathogen in the world. An estimated one-third of humans harbor Mtb in a dormant state. These asymptomatic, latent infections impede tuberculosis eradication due to the long-term potential for reactivation. Dormant Mtb has reduced enzymatic activity, but hydrolases that remain active facilitate pathogen survival. We targeted Mtb esterases, a diverse set of enzymes in the serine hydrolase family, and studied their activities using both activity-based probes (ABPs) and fluorogenic esterase substrates. These small-molecule probes revealed functional esterases in active, dormant, and reactivating cultures. Using ABPs, we identified five esterases that remained active in dormant Mtb, including LipM (Rv2284), LipN (Rv2970c), CaeA (Rv2224c), Rv0183, and Rv1683. Three of these, CaeA, Rv0183, and Rv1683, were catalytically active in all three culture conditions. Fluorogenic probes additionally revealed LipH (Rv1399c), Culp1 (Rv1984c), and Rv3036c esterase activity in dormant and active cultures. Esterases with persistent activity are potential diagnostic biomarkers or therapeutic targets for Mtb-infected individuals with latent or active tuberculosis.
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Affiliation(s)
- Katie R. Tallman
- Program in Chemical Biology and Department of Biomedical Engineering, Oregon Health & Science University, Mail Code CL3B, 2730 S.W. Moody Avenue, Portland, Oregon 97201, United States
| | - Samantha R. Levine
- Program in Chemical Biology and Department of Biomedical Engineering, Oregon Health & Science University, Mail Code CL3B, 2730 S.W. Moody Avenue, Portland, Oregon 97201, United States
| | - Kimberly E. Beatty
- Program in Chemical Biology and Department of Biomedical Engineering, Oregon Health & Science University, Mail Code CL3B, 2730 S.W. Moody Avenue, Portland, Oregon 97201, United States
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21
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Tsai IF, Kuo CP, Lin AB, Chien MN, Ho HT, Wei TY, Wu CL, Lu YT. Potential effect of ezetimibe against Mycobacterium tuberculosis infection in type II diabetes. Respirology 2016; 22:559-566. [PMID: 27879023 DOI: 10.1111/resp.12948] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 08/11/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVE Tuberculosis (TB) risk might be increased in patients with diabetes by factors other than hyperglycaemia, such as dyslipidaemia. Host lipids are essential energy sources used by mycobacteria to persist in a latent TB state. A potential therapy targeting cholesterol catabolism of mycobacteria has been proposed, but the potential of cholesterol-lowering drugs as anti-TB therapy is unclear. The purpose of this study was to determine the effects of ezetimibe, a 2-azetidinone cholesterol absorption inhibitor, on intracellular mycobacteria survival and dormancy. METHODS Intracellular mycobacteria survival was determined by measurements of ATP activity and colony-formation units (CFUs). Gene expression profiles of hypoxia-induced dormant Mycobacterium tuberculosis (Mtb) were analysed by real-time PCR. Flow cytometry and microscopy analysis were used to measure the lipid loads of human macrophages with or without ezetimibe treatment. QuantiFERON-TB Gold In-Tube (QFT-G-IT) assays were performed to diagnose latent TB infection. The levels of intracellular cholesterol/ triglyceride were measured by an enzymatic fluorometric method. RESULTS Ezetimibe was capable of effectively lowering intracellular growth of Mtb and hypoxia-induced dormant Mtb. There was a significant decrease in Mtb growth in leucocytes from ezetimibe-treated patients with diabetes in terms of ATP levels of intracellular mycobacteria and CFU formation. Also, patients receiving ezetimibe therapy had a lower prevalence of latent TB and had lower intracellular lipid contents. CONCLUSION Ezetimibe, which is a currently marketed drug, could hold promise as an adjunctive, host-directed therapy for TB.
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Affiliation(s)
- I-Fang Tsai
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Chiu-Ping Kuo
- Division of Chest Medicine, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan
| | - Andrew B Lin
- Biology Department, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ming-Nan Chien
- Department of Endocrinology and Metabolism, MacKay Memorial Hospital, Taipei, Taiwan
| | - Hsin-Tsung Ho
- Department of Laboratory Medicine, MacKay Memorial Hospital, Taipei, Taiwan.,Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
| | - Tsai-Yin Wei
- Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan
| | - Chien-Liang Wu
- Division of Chest Medicine, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan.,MacKay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan
| | - Yen-Ta Lu
- Division of Chest Medicine, Department of Internal Medicine, MacKay Memorial Hospital, Taipei, Taiwan.,Department of Medicine, MacKay Medical College, New Taipei City, Taiwan
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22
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Effects of Lipid-Lowering Drugs on Vancomycin Susceptibility of Mycobacteria. Antimicrob Agents Chemother 2016; 60:6193-9. [PMID: 27503643 DOI: 10.1128/aac.00872-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/17/2016] [Indexed: 12/24/2022] Open
Abstract
Tuberculosis is still a cause of major concern, partly due to the emergence of multidrug-resistant strains. New drugs are therefore needed. Vancomycin can target mycobacteria with cell envelope deficiency. In this study, we used a vancomycin susceptibility assay to detect drugs hampering lipid synthesis in Mycobacterium bovis BCG and in Mycobacterium tuberculosis We tested three drugs already used to treat human obesity: tetrahydrolipstatin (THL), simvastatin, and fenofibrate. Only vancomycin and THL were able to synergize on M. bovis BCG and on M. tuberculosis, although mycobacteria could also be inhibited by simvastatin alone. Lipid analysis allowed us to identify several lipid modifications in M. tuberculosis H37Rv treated with those drugs. THL treatment mainly reduced the phthiocerol dimycocerosate (PDIM) content in the mycobacterial cell wall, providing an explanation for the synergy, since PDIM deficiency has been related to vancomycin susceptibility. Proteomic analysis suggested that bacteria treated with THL, in contrast to bacteria treated with simvastatin, tried to recover, inducing, among other reactions, lipid synthesis. The combination of THL and vancomycin should be considered a promising solution in developing new strategies to treat multidrug-resistant tuberculosis.
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23
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Abstract
Bacterial sphingomyelinases and phospholipases are a heterogeneous group of esterases which are usually surface associated or secreted by a wide variety of Gram-positive and Gram-negative bacteria. These enzymes hydrolyze sphingomyelin and glycerophospholipids, respectively, generating products identical to the ones produced by eukaryotic enzymes which play crucial roles in distinct physiological processes, including membrane dynamics, cellular signaling, migration, growth, and death. Several bacterial sphingomyelinases and phospholipases are essential for virulence of extracellular, facultative, or obligate intracellular pathogens, as these enzymes contribute to phagosomal escape or phagosomal maturation avoidance, favoring tissue colonization, infection establishment and progression, or immune response evasion. This work presents a classification proposal for bacterial sphingomyelinases and phospholipases that considers not only their enzymatic activities but also their structural aspects. An overview of the main physiopathological activities is provided for each enzyme type, as are examples in which inactivation of a sphingomyelinase- or a phospholipase-encoding gene impairs the virulence of a pathogen. The identification of sphingomyelinases and phospholipases important for bacterial pathogenesis and the development of inhibitors for these enzymes could generate candidate vaccines and therapeutic agents, which will diminish the impacts of the associated human and animal diseases.
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24
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Kumar A, Sharma A, Kaur G, Makkar P, Kaur J. Functional characterization of hypothetical proteins of Mycobacterium tuberculosis with possible esterase/lipase signature: a cumulative in silico and in vitro approach. J Biomol Struct Dyn 2016; 35:1226-1243. [DOI: 10.1080/07391102.2016.1174738] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Arbind Kumar
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Aashish Sharma
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Gurkamaljit Kaur
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Pooja Makkar
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh 160014, India
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25
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Dang G, Cao J, Cui Y, Song N, Chen L, Pang H, Liu S. Characterization of Rv0888, a Novel Extracellular Nuclease from Mycobacterium tuberculosis. Sci Rep 2016; 6:19033. [PMID: 26742696 PMCID: PMC4733049 DOI: 10.1038/srep19033] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 12/02/2015] [Indexed: 02/07/2023] Open
Abstract
Bacterial extracellular nucleases play important roles in virulence, biofilm formation, utilization of extracellular DNA as a nutrient, and degradation of neutrophil DNA extracellular traps. However, there is no current data available for extracellular nucleases derived from M. tuberculosis. Herein, we have identified and characterized Rv0888, an extracellular nuclease in M. tuberculosis. The protein was overexpressed in E. coli, and the purified Rv0888 protein was found to require divalent cations for activity, with an optimal temperature and pH of 41 °C and 6.5, respectively. Further results demonstrated that Rv0888 nuclease activity could be inhibited by four Chinese medicine monomers. Based on sequence analysis, Rv0888 nuclease exhibited no homology with any known extracellular nucleases, indicating that Rv0888 is a novel nuclease. Site-directed mutagenesis studies revealed that the H353, D387, and D438 residues play catalytic roles in Rv0888. In vivo infection studies confirmed that Rv0888 is required for infection and is related to pathogenicity, as the persistent ability of recombinant Mycobacterium smegmatis (rMS) Rv0888NS/MS and Rv0888S/MS is significantly higher than pMV262/MS in the lung tissue, and the Rv0888NS/MS and Rv0888S/MS could produce pathological changes in the mice lung. These results show that Rv0888 is relevant to pathogenicity of M. tuberculosis.
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Affiliation(s)
- Guanghui Dang
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Nangang Dist, Harbin 15000, PR China
| | - Jun Cao
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Nangang Dist, Harbin 15000, PR China
| | - Yingying Cui
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Nangang Dist, Harbin 15000, PR China
| | - Ningning Song
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Nangang Dist, Harbin 15000, PR China
| | - Liping Chen
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Nangang Dist, Harbin 15000, PR China
| | - Hai Pang
- School of Medicine, Tsinghua University, Beijing, 100084, China
| | - Siguo Liu
- Division of Bacterial Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Nangang Dist, Harbin 15000, PR China
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26
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Verma D, Das L, Gambhir V, Dikshit KL, Varshney GC. Heterogeneity among Homologs of Cutinase-Like Protein Cut5 in Mycobacteria. PLoS One 2015; 10:e0133186. [PMID: 26177502 PMCID: PMC4503659 DOI: 10.1371/journal.pone.0133186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 06/23/2015] [Indexed: 11/29/2022] Open
Abstract
The study of genomic variability within various pathogenic and non-pathogenic strains of mycobacteria provides insight into their evolution and pathogenesis. The mycobacterial genome encodes seven cutinase-like proteins and each one of these exhibit distinct characteristics. We describe the presence of Cut5, a member of the cutinase family, in mycobacteria and the existence of a unique genomic arrangement in the cut5 gene of M. tuberculosis (Mtb) strains. A single nucleotide (T) insertion is observed in the cut5 gene, which is specific for Mtb strains. Using in silico analysis and RT-PCR, we demonstrate the transcription of Rv3724/cut5 as Rv3724a/cut5a and Rv3724b/cut5b in Mtb H37Rv and as full length cut5 in M. bovis. Cut5b protein of Mtb H37Rv (MtbCut5b) was found to be antigenically similar to its homologs in M. bovis and M. smegmatis, without any observed cross-reactivity with other Mtb cutinases. Also, the presence of Cut5b in Mtb and its homologs in M. bovis and M. smegmatis were confirmed by western blotting using antibodies raised against recombinant Cut5b. In Mtb H37Rv, Cut5b was found to be localized in the cell wall, cytosol and membrane fractions. We also report the vast prevalence of Cut5 homologs in pathogenic and non pathogenic species of mycobacteria. In silico analysis revealed that this protein has three possible organizations in mycobacteria. Also, a single nucleotide (T) insertion in Mtb strains and varied genomic arrangements within mycobacterial species make Rv3724/Cut5 a potential candidate that can be exploited as a biomarker in Mtb infection.
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Affiliation(s)
- Deepshikha Verma
- Cell biology and Immunology Division, CSIR-Institute of Microbial Technology, Chandigarh-, India
| | - Lahari Das
- Cell biology and Immunology Division, CSIR-Institute of Microbial Technology, Chandigarh-, India
| | - Vandana Gambhir
- Cell biology and Immunology Division, CSIR-Institute of Microbial Technology, Chandigarh-, India
| | - Kanak Lata Dikshit
- Cell biology and Immunology Division, CSIR-Institute of Microbial Technology, Chandigarh-, India
| | - Grish C. Varshney
- Cell biology and Immunology Division, CSIR-Institute of Microbial Technology, Chandigarh-, India
- * E-mail:
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27
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Speer A, Sun J, Danilchanka O, Meikle V, Rowland JL, Walter K, Buck BR, Pavlenok M, Hölscher C, Ehrt S, Niederweis M. Surface hydrolysis of sphingomyelin by the outer membrane protein Rv0888 supports replication of Mycobacterium tuberculosis in macrophages. Mol Microbiol 2015; 97:881-97. [PMID: 26036301 DOI: 10.1111/mmi.13073] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2015] [Indexed: 12/19/2022]
Abstract
Sphingomyelinases secreted by pathogenic bacteria play important roles in host-pathogen interactions ranging from interfering with phagocytosis and oxidative burst to iron acquisition. This study shows that the Mtb protein Rv0888 possesses potent sphingomyelinase activity cleaving sphingomyelin, a major lipid in eukaryotic cells, into ceramide and phosphocholine, which are then utilized by Mtb as carbon, nitrogen and phosphorus sources, respectively. An Mtb rv0888 deletion mutant did not grow on sphingomyelin as a sole carbon source anymore and replicated poorly in macrophages indicating that Mtb utilizes sphingomyelin during infection. Rv0888 is an unusual membrane protein with a surface-exposed C-terminal sphingomyelinase domain and a putative N-terminal channel domain that mediated glucose and phosphocholine uptake across the outer membrane in an M. smegmatis porin mutant. Hence, we propose to name Rv0888 as SpmT (sphingomyelinase of Mycobacterium tuberculosis). Erythrocyte membranes contain up to 27% sphingomyelin. The finding that Rv0888 accounts for half of Mtb's hemolytic activity is consistent with its sphingomyelinase activity and the observation that Rv0888 levels are increased in the presence of erythrocytes and sphingomyelin by 5- and 100-fold, respectively. Thus, Rv0888 is a novel outer membrane protein that enables Mtb to utilize sphingomyelin as a source of several essential nutrients during intracellular growth.
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Affiliation(s)
- Alexander Speer
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jim Sun
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Olga Danilchanka
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Virginia Meikle
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jennifer L Rowland
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kerstin Walter
- Infection Immunology, Research Center Borstel, Borstel, Germany.,German Center for Infection Research, Borstel, Germany
| | - Bradford R Buck
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Mikhail Pavlenok
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Christoph Hölscher
- Infection Immunology, Research Center Borstel, Borstel, Germany.,German Center for Infection Research, Borstel, Germany.,Cluster of Excellence 'Inflammation at Interfaces', Christian-Albrechts-University, Kiel, Germany
| | - Sabine Ehrt
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, NY, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA
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28
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Ravindran MS, Rao SPS, Cheng X, Shukla A, Cazenave-Gassiot A, Yao SQ, Wenk MR. Targeting lipid esterases in mycobacteria grown under different physiological conditions using activity-based profiling with tetrahydrolipstatin (THL). Mol Cell Proteomics 2013; 13:435-48. [PMID: 24345785 DOI: 10.1074/mcp.m113.029942] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tetrahydrolipstatin (THL) is bactericidal but its precise target spectrum is poorly characterized. Here, we used a THL analog and activity-based protein profiling to identify target proteins after enrichment from whole cell lysates of Mycobacterium bovis Bacillus Calmette-Guérin cultured under replicating and non-replicating conditions. THL targets α/β-hydrolases, including many lipid esterases (LipD, G, H, I, M, N, O, V, W, and TesA). Target protein concentrations and total esterase activity correlated inversely with cellular triacylglycerol upon entry into and exit from non-replicating conditions. Cellular overexpression of lipH and tesA led to decreased THL susceptibility thus providing functional validation. Our results define the target spectrum of THL in a biological species with particularly diverse lipid metabolic pathways. We furthermore derive a conceptual approach that demonstrates the use of such THL probes for the characterization of substrate recognition by lipases and related enzymes.
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Affiliation(s)
- Madhu Sudhan Ravindran
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456
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29
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Characterization of an acid inducible lipase Rv3203 from Mycobacterium tuberculosis H37Rv. Mol Biol Rep 2013; 41:285-96. [DOI: 10.1007/s11033-013-2861-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
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30
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Hahn J, Seeber F, Kolodziej H, Ignatius R, Laue M, Aebischer T, Klotz C. High sensitivity of Giardia duodenalis to tetrahydrolipstatin (orlistat) in vitro. PLoS One 2013; 8:e71597. [PMID: 23977083 PMCID: PMC3747212 DOI: 10.1371/journal.pone.0071597] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 07/06/2013] [Indexed: 11/18/2022] Open
Abstract
Giardiasis, a gastrointestinal disease caused by Giardia duodenalis, is currently treated mainly with nitroimidazoles, primarily metronidazole (MTZ). Treatment failure rates of up to 20 percent reflect the compelling need for alternative treatment options. Here, we investigated whether orlistat, a drug approved to treat obesity, represents a potential therapeutic agent against giardiasis. We compared the growth inhibitory effects of orlistat and MTZ on a long-term in vitro culture adapted G. duodenalis strain, WB-C6, and on a new isolate, 14-03/F7, from a patient refractory to MTZ treatment using a resazurin assay. The giardiacidal concentration of the drugs and their combined in vitro efficacy was determined by median-effect analysis. Morphological changes after treatment were analysed by light and electron microscopy. Orlistat inhibited the in vitro growth of G. duodenalis at low micromolar concentrations, with isolate 14-03/F7 (IC5024h = 2.8 µM) being more sensitive than WB-C6 (IC5024h = 6.2 µM). The effect was significantly more potent compared to MTZ (IC5024h = 4.3 µM and 11.0 µM, respectively) and led to specific undulated morphological alterations on the parasite surface. The giardiacidal concentration of orlistat was >14 µM for 14-03/F7 and >43 µM for WB-C6, respectively. Importantly, the combination of both drugs revealed no interaction on their inhibitory effects. We demonstrate that orlistat is a potent inhibitor of G. duodenalis growth in vitro and kills parasites at concentrations achievable in the gut by approved treatment regimens for obesity. We therefore propose to investigate orlistat in controlled clinical studies as a new drug in giardiasis.
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Affiliation(s)
- Juliane Hahn
- Institute of Pharmacy, Pharmaceutical Biology, Freie Universität Berlin, Berlin, Germany
| | - Frank Seeber
- Mycotic and Parasitic Agents and Mycobacteria, Department of Infectious Diseases, Robert Koch-Institut, Berlin, Germany
| | - Herbert Kolodziej
- Institute of Pharmacy, Pharmaceutical Biology, Freie Universität Berlin, Berlin, Germany
| | - Ralf Ignatius
- Institute of Tropical Medicine and International Health, Charité – Universitätsmedizin Berlin, Berlin, Germany
| | - Michael Laue
- Advanced Light and Electron Microscopy, Centre for Biological Threats and Special Pathogens, Robert Koch-Institut, Berlin, Germany
| | - Toni Aebischer
- Mycotic and Parasitic Agents and Mycobacteria, Department of Infectious Diseases, Robert Koch-Institut, Berlin, Germany
| | - Christian Klotz
- Mycotic and Parasitic Agents and Mycobacteria, Department of Infectious Diseases, Robert Koch-Institut, Berlin, Germany
- * E-mail:
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31
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Dedieu L, Serveau-Avesque C, Canaan S. Identification of residues involved in substrate specificity and cytotoxicity of two closely related cutinases from Mycobacterium tuberculosis. PLoS One 2013; 8:e66913. [PMID: 23843969 PMCID: PMC3699616 DOI: 10.1371/journal.pone.0066913] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 05/11/2013] [Indexed: 11/20/2022] Open
Abstract
The enzymes belonging to the cutinase family are serine enzymes active on a large panel of substrates such as cutin, triacylglycerols, and phospholipids. In the M. tuberculosis H37Rv genome, seven genes coding for cutinase-like proteins have been identified with strong immunogenic properties suggesting a potential role as vaccine candidates. Two of these enzymes which are secreted and highly homologous, possess distinct substrates specificities. Cfp21 is a lipase and Cut4 is a phospholipase A2, which has cytotoxic effects on macrophages. Structural overlay of their three-dimensional models allowed us to identify three areas involved in the substrate binding process and to shed light on this substrate specificity. By site-directed mutagenesis, residues present in these Cfp21 areas were replaced by residues occurring in Cut4 at the same location. Three mutants acquired phospholipase A1 and A2 activities and the lipase activities of two mutants were 3 and 15 fold greater than the Cfp21 wild type enzyme. In addition, contrary to mutants with enhanced lipase activity, mutants that acquired phospholipase B activities induced macrophage lysis as efficiently as Cut4 which emphasizes the relationship between apparent phospholipase A2 activity and cytotoxicity. Modification of areas involved in substrate specificity, generate recombinant enzymes with higher activity, which may be more immunogenic than the wild type enzymes and could therefore constitute promising candidates for antituberculous vaccine production.
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Affiliation(s)
- Luc Dedieu
- CNRS - Aix-Marseille Université - Enzymologie Interfaciale et Physiologie de la Lipolyse - UMR 7282, Marseille, France
| | - Carole Serveau-Avesque
- CNRS - Aix-Marseille Université - Enzymologie Interfaciale et Physiologie de la Lipolyse - UMR 7282, Marseille, France
| | - Stéphane Canaan
- CNRS - Aix-Marseille Université - Enzymologie Interfaciale et Physiologie de la Lipolyse - UMR 7282, Marseille, France
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32
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Sultana R, Vemula MH, Banerjee S, Guruprasad L. The PE16 (Rv1430) of Mycobacterium tuberculosis is an esterase belonging to serine hydrolase superfamily of proteins. PLoS One 2013; 8:e55320. [PMID: 23383323 PMCID: PMC3562317 DOI: 10.1371/journal.pone.0055320] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Accepted: 12/21/2012] [Indexed: 11/19/2022] Open
Abstract
The PE and PPE multigene families, first discovered during the sequencing of M. tuberculosis H37Rv genome are responsible for antigenic variation and have been shown to induce increased humoral and cell mediated immune response in the host. Using the bioinformatics tools, we had earlier reported that the 225 amino acid residue PE-PPE domain (Pfam: PF08237) common to some PE and PPE proteins has a “serine α/β hydrolase” fold and conserved Ser, Asp and His catalytic triad characteristic of lipase, esterase and cutinase activities. In order to prove experimentally that PE-PPE domain is indeed a serine hydrolase, we have cloned the full-length Rv1430 and its PE-PPE domain into pET-28a vector, expressed the proteins in E. coli and purified to homogeneity. The activity assays of both purified proteins were carried out using p-nitrophenyl esters of aliphatic carboxylic acids with varying chain length (C2–C16) to study the substrate specificity. To characterize the active site of the PE-PPE domain, we mutated the Ser199 to Ala. The activity of the protein in the presence of serine protease inhibitor- PMSF and the mutant protein were measured. Our results reveal that Rv1430 and its PE-PPE domain possess esterase activity and hydrolyse short to medium chain fatty acid esters with the highest specific activity for pNPC6 at 37°C, 38°C and pH 7.0, 8.0. The details of this work and the observed results are reported in this manuscript.
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Affiliation(s)
- Rafiya Sultana
- School of Chemistry, University of Hyderabad, Hyderabad, India
| | - Mani Harika Vemula
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Sharmishta Banerjee
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Hyderabad, India
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33
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Dedieu L, Serveau-Avesque C, Kremer L, Canaan S. Mycobacterial lipolytic enzymes: A gold mine for tuberculosis research. Biochimie 2013; 95:66-73. [DOI: 10.1016/j.biochi.2012.07.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/10/2012] [Indexed: 10/28/2022]
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34
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Saravanan P, Avinash H, Dubey VK, Patra S. Targeting essential cell wall lipase Rv3802c for potential therapeutics against tuberculosis. J Mol Graph Model 2012; 38:235-42. [PMID: 23085165 DOI: 10.1016/j.jmgm.2012.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 06/15/2012] [Accepted: 06/19/2012] [Indexed: 11/17/2022]
Abstract
Cell wall and lipid metabolism plays a vital role in the survival and infection of Mycobacterium tuberculosis. Increase in the incidences of life-threatening multidrug-resistant (MDR) and extreme drug-resistant (XDR) tuberculosis worsens the existing scenario and urge the need of new druggable targets and new drugs. Targeting Rv3802c, an essential cell wall lipase, can open up a new arsenal to fight the dreadful opportunistic pathogen. Our current study highlights the essentiality of Rv3802c. Its 3D structure is predicted for the first time which provides insight in identifying the ligand binding sites. Our analysis showed Rv3802c is highly conserved throughout mycobacterial species with no significant sequence homolog found in human proteome. Virtual screening followed by comparative docking studies of Rv3802c with its closest human structural homolog has been carried out to identify potential inhibitors effective towards mycobacterial proteins. Two diverse molecules from ZINC database, ZINC26726377 and ZINC43866786 have been identified as potential inhibitors effective towards Rv3802c based on the difference in predicted binding free energy of -3.99 and -3.28kcal/mol respectively. Rv3802c is a promising drug target and also a step towards understanding and targeting the pathogen's cell wall and lipid metabolism simultaneously to combat tuberculosis.
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Affiliation(s)
- Parameswaran Saravanan
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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35
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MmPPOX inhibits Mycobacterium tuberculosis lipolytic enzymes belonging to the hormone-sensitive lipase family and alters mycobacterial growth. PLoS One 2012; 7:e46493. [PMID: 23029536 PMCID: PMC3460867 DOI: 10.1371/journal.pone.0046493] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 09/05/2012] [Indexed: 11/19/2022] Open
Abstract
Lipid metabolism plays an important role during the lifetime of Mycobacterium tuberculosis, the causative agent of tuberculosis. Although M. tuberculosis possesses numerous lipolytic enzymes, very few have been characterized yet at a biochemical/pharmacological level. This study was devoted to the M. tuberculosis lipolytic enzymes belonging to the Hormone-Sensitive Lipase (HSL) family, which encompasses twelve serine hydrolases closely related to the human HSL. Among them, nine were expressed, purified and biochemically characterized using a broad range of substrates. In vitro enzymatic inhibition studies using the recombinant HSL proteins, combined with mass spectrometry analyses, revealed the potent inhibitory activity of an oxadiazolone compound, named MmPPOX. In addition, we provide evidence that MmPPOX alters mycobacterial growth. Overall, these findings suggest that the M. tuberculosis HSL family displays important metabolic functions, thus opening the way to further investigations linking the involvement of these enzymes in mycobacterial growth.
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36
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Yang P, Wang M, Liu K, Ngai MH, Sheriff O, Lear MJ, Sze SK, He CY, Yao SQ. Parasite‐Based Screening and Proteome Profiling Reveal Orlistat, an FDA‐Approved Drug, as a Potential Anti
Trypanosoma brucei
Agent
[
]. Chemistry 2012; 18:8403-13. [DOI: 10.1002/chem.201200482] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 03/22/2012] [Indexed: 12/21/2022]
Affiliation(s)
- Peng‐Yu Yang
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore), Fax: (+65) 6779‐1691
| | - Min Wang
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543 (Singapore)
| | - Kai Liu
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543 (Singapore)
| | - Mun Hong Ngai
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore), Fax: (+65) 6779‐1691
| | - Omar Sheriff
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543 (Singapore)
| | - Martin J. Lear
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore), Fax: (+65) 6779‐1691
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore)
| | - Cynthia Y. He
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543 (Singapore)
| | - Shao Q. Yao
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore), Fax: (+65) 6779‐1691
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37
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Zhao S, Shi J, Zhang C, Zhao Y, Mao F, Yang W, Bai B, Zhang H, Shi C, Xu Z. Monoclonal antibodies against a Mycobacterium tuberculosis Ag85B-Hsp16.3 fusion protein. Hybridoma (Larchmt) 2012; 30:427-32. [PMID: 22008069 DOI: 10.1089/hyb.2011.0047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The secreted Mycobacterium tuberculosis (MTB) proteins, Ag85B and Hsp16.3, have been the focus of intensive research in recent years. These proteins have high sensitivity in bacterium-negative tuberculosis (TB) patients, and are valuable for the rapid diagnosis of bacterium-negative TB. Fusion proteins including multiple antigens such as Ag85B and Hsp16.3 provide improved sensitivity and specificity for serological diagnosis of active TB compared with a single antigen. Many studies have shown that the production of MAbs recognizing a specific repertoire of M. tuberculosis antigens and the tests based on monoclonal antibodies have been found to be valuable in positive detection of TB, particularly for smear-positive pulmonary TB. A number of MAbs are currently used for serodiagnosis of TB. Therefore, an Ag85B-Hsp16.3 fusion protein was expressed and purified using an E. coli system in this study. Three Ag85B-Hsp16.3 fusion protein-specific MAbs were generated by routine murine hybridoma techniques. The titer, specificity, and relative affinity of all three MAbs were determined by ELISA and the serological responses were analyzed. The levels of antigens in a proportion of TB patients were shown to be significantly higher than those in healthy controls. The sensitivity and specificity of the currently available detection systems is likely to be improved by the employment of a combination of these MAbs with others that are already in use.
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Affiliation(s)
- Shanmin Zhao
- Division of Infection and Immunology, Laboratory Animals Center, Fourth Military Medical University, Xi'an, Shaanxi Province, China
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38
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Seeliger JC, Holsclaw CM, Schelle MW, Botyanszki Z, Gilmore SA, Tully SE, Niederweis M, Cravatt BF, Leary JA, Bertozzi CR. Elucidation and chemical modulation of sulfolipid-1 biosynthesis in Mycobacterium tuberculosis. J Biol Chem 2011; 287:7990-8000. [PMID: 22194604 PMCID: PMC3318749 DOI: 10.1074/jbc.m111.315473] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Mycobacterium tuberculosis possesses unique cell-surface lipids that have been implicated in virulence. One of the most abundant is sulfolipid-1 (SL-1), a tetraacyl-sulfotrehalose glycolipid. Although the early steps in SL-1 biosynthesis are known, the machinery underlying the final acylation reactions is not understood. We provide genetic and biochemical evidence for the activities of two proteins, Chp1 and Sap (corresponding to gene loci rv3822 and rv3821), that complete this pathway. The membrane-associated acyltransferase Chp1 accepts a synthetic diacyl sulfolipid and transfers an acyl group regioselectively from one donor substrate molecule to a second acceptor molecule in two successive reactions to yield a tetraacylated product. Chp1 is fully active in vitro, but in M. tuberculosis, its function is potentiated by the previously identified sulfolipid transporter MmpL8. We also show that the integral membrane protein Sap and MmpL8 are both essential for sulfolipid transport. Finally, the lipase inhibitor tetrahydrolipstatin disrupts Chp1 activity in M. tuberculosis, suggesting an avenue for perturbing SL-1 biosynthesis in vivo. These data complete the SL-1 biosynthetic pathway and corroborate a model in which lipid biosynthesis and transmembrane transport are coupled at the membrane-cytosol interface through the activity of multiple proteins, possibly as a macromolecular complex.
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Affiliation(s)
- Jessica C Seeliger
- Department of Chemistry, University of California, Berkeley, California 94720-1460, USA
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39
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Monoclonal Antibody Against a Mycobacterium tuberculosis Ag85B-Hsp16.3 Fusion Protein. Hybridoma (Larchmt) 2011. [DOI: 10.1089/hyb.2011.0068.mab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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40
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Banerjee R, Vats P, Dahale S, Kasibhatla SM, Joshi R. Comparative genomics of cell envelope components in mycobacteria. PLoS One 2011; 6:e19280. [PMID: 21573108 PMCID: PMC3089613 DOI: 10.1371/journal.pone.0019280] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Accepted: 03/25/2011] [Indexed: 12/26/2022] Open
Abstract
Mycobacterial cell envelope components have been a major focus of research due to their unique features that confer intrinsic resistance to antibiotics and chemicals apart from serving as a low-permeability barrier. The complex lipids secreted by Mycobacteria are known to evoke/repress host-immune response and thus contribute to its pathogenicity. This study focuses on the comparative genomics of the biosynthetic machinery of cell wall components across 21-mycobacterial genomes available in GenBank release 179.0. An insight into survival in varied environments could be attributed to its variation in the biosynthetic machinery. Gene-specific motifs like 'DLLAQPTPAW' of ufaA1 gene, novel functional linkages such as involvement of Rv0227c in mycolate biosynthesis; Rv2613c in LAM biosynthesis and Rv1209 in arabinogalactan peptidoglycan biosynthesis were detected in this study. These predictions correlate well with the available mutant and coexpression data from TBDB. It also helped to arrive at a minimal functional gene set for these biosynthetic pathways that complements findings using TraSH.
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Affiliation(s)
- Ruma Banerjee
- Bioinformatics Group, Centre for Development of Advanced Computing, Pune University Campus, Pune, Maharashtra, India
| | - Pankaj Vats
- Bioinformatics Group, Centre for Development of Advanced Computing, Pune University Campus, Pune, Maharashtra, India
| | - Sonal Dahale
- Bioinformatics Group, Centre for Development of Advanced Computing, Pune University Campus, Pune, Maharashtra, India
| | - Sunitha Manjari Kasibhatla
- Bioinformatics Group, Centre for Development of Advanced Computing, Pune University Campus, Pune, Maharashtra, India
| | - Rajendra Joshi
- Bioinformatics Group, Centre for Development of Advanced Computing, Pune University Campus, Pune, Maharashtra, India
- * E-mail:
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41
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Watching intracellular lipolysis in mycobacteria using time lapse fluorescence microscopy. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:234-41. [DOI: 10.1016/j.bbalip.2011.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 12/15/2010] [Accepted: 01/06/2011] [Indexed: 11/22/2022]
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42
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West NP, Cergol KM, Xue M, Randall EJ, Britton WJ, Payne RJ. Inhibitors of an essential mycobacterial cell wall lipase (Rv3802c) as tuberculosis drug leads. Chem Commun (Camb) 2011; 47:5166-8. [DOI: 10.1039/c0cc05635a] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Singh G, Singh G, Jadeja D, Kaur J. Lipid hydrolizing enzymes in virulence: Mycobacterium tuberculosis as a model system. Crit Rev Microbiol 2010; 36:259-69. [PMID: 20500016 DOI: 10.3109/1040841x.2010.482923] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This review is focused on the virulent traits of lipolytic enzymes from bacteria with special emphasis on Mycobacterium tuberculosis. In vivo, triacylglycerols in the form of inclusion bodies are present in tubercle bacilli in the lungs. This pathogenic bacterium possesses a lipase gene (Lip) family, which is expressed and differentially regulated under a variety of in vitro conditions. Not much research work has been carried out on these lipolytic enzymes. A better understanding of lipolytic enzymes in mycobacteria would lead to develop new strategies for tuberculosis treatment. The present review highlights the recent work done in the field of mycobacterium lipolytic enzymes and their involvement in the virulence and pathogenicity.
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Affiliation(s)
- Gurdyal Singh
- Department of Biotechnology, Panjab University, Chandigarh-160014, India
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44
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Crellin PK, Vivian JP, Scoble J, Chow FM, West NP, Brammananth R, Proellocks NI, Shahine A, Le Nours J, Wilce MCJ, Britton WJ, Coppel RL, Rossjohn J, Beddoe T. Tetrahydrolipstatin inhibition, functional analyses, and three-dimensional structure of a lipase essential for mycobacterial viability. J Biol Chem 2010; 285:30050-60. [PMID: 20656688 PMCID: PMC2943268 DOI: 10.1074/jbc.m110.150094] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 07/21/2010] [Indexed: 11/06/2022] Open
Abstract
The highly complex and unique mycobacterial cell wall is critical to the survival of Mycobacteria in host cells. However, the biosynthetic pathways responsible for its synthesis are, in general, incompletely characterized. Rv3802c from Mycobacterium tuberculosis is a partially characterized phospholipase/thioesterase encoded within a genetic cluster dedicated to the synthesis of core structures of the mycobacterial cell wall, including mycolic acids and arabinogalactan. Enzymatic assays performed with purified recombinant proteins Rv3802c and its close homologs from Mycobacterium smegmatis (MSMEG_6394) and Corynebacterium glutamicum (NCgl2775) show that they all have significant lipase activities that are inhibited by tetrahydrolipstatin, an anti-obesity drug that coincidently inhibits mycobacterial cell wall biosynthesis. The crystal structure of MSMEG_6394, solved to 2.9 Å resolution, revealed an α/β hydrolase fold and a catalytic triad typically present in esterases and lipases. Furthermore, we demonstrate direct evidence of gene essentiality in M. smegmatis and show the structural consequences of loss of MSMEG_6394 function on the cellular integrity of the organism. These findings, combined with the predicted essentiality of Rv3802c in M. tuberculosis, indicate that the Rv3802c family performs a fundamental and indispensable lipase-associated function in mycobacteria.
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Affiliation(s)
- Paul K Crellin
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria 3800, Australia.
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45
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Schué M, Maurin D, Dhouib R, Bakala N'Goma JC, Delorme V, Lambeau G, Carrière F, Canaan S. Two cutinase-like proteins secreted by Mycobacterium tuberculosis show very different lipolytic activities reflecting their physiological function. FASEB J 2010; 24:1893-903. [PMID: 20103719 DOI: 10.1096/fj.09-144766] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cutinases are extracellular enzymes that are able to degrade cutin, a polyester protecting plant leaves and many kinds of lipids. Although cutinases are mainly found in phytopathogenic fungi or bacteria, 7 genes related to the cutinase family have been predicted in the genome of Mycobacterium tuberculosis. These genes may encode proteins that are involved in the complex lipid metabolism of the bacterium. Here, we report on the biochemical characterization of two secreted proteins of M. tuberculosis, Rv1984c and Rv3452, belonging to the cutinase family. Although their amino acid sequence shows 50% identity with that of the well-characterized cutinase from Fusarium solani pisi, and a high level of homology has been found to exist between these two enzymes, they show distinct substrate specificities. Rv1984c preferentially hydrolyzes medium-chain carboxylic esters and monoacylglycerols, whereas Rv3452 behaves like a phospholipase A(2), and it is able to induce macrophage lysis. The tetrahydrolipstatin inhibitor, a specific lipase inhibitor, abolishes the activity of both enzymes. Site-directed mutagenesis was performed to identify the catalytic triad of Rv1984c. Structural models for Rv1984c and Rv3452 were built, based on the crystal structure of F. solani cutinase, with a view to investigating the contribution of specific residues to the substrate specificity. Our findings open new prospects for investigating the physiological roles of cutinase-like proteins in the lipid metabolism and virulence of M. tuberculosis.
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Affiliation(s)
- Mathieu Schué
- Centre National de la Recherche Scientifique, Aix-Marseille Université, Enzymologie Interfaciale et Physiologie de la Lipolyse UPR 9025, Marseille, France
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46
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Elamin AA, Stehr M, Oehlmann W, Singh M. The mycolyltransferase 85A, a putative drug target of Mycobacterium tuberculosis: development of a novel assay and quantification of glycolipid-status of the mycobacterial cell wall. J Microbiol Methods 2009; 79:358-63. [PMID: 19857528 DOI: 10.1016/j.mimet.2009.10.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 10/15/2009] [Accepted: 10/16/2009] [Indexed: 11/25/2022]
Abstract
The enzymes of the antigen 85 complex (Ag85A, B, and C) possess mycolyltransferase activity and catalyze the synthesis of the most abundant glycolipid of the mycobacterial cell wall, the cord factor. The cord factor (trehalose 6,6'-dimycolate, TDM) is essential for the integrity of the mycobacterial cell wall and pathogenesis of the bacillus. Thus, TDM biosynthesis is regarded as a potential drug target for control of Mycobacterium tuberculosis infections. Trehalose 6,6'-dimycolate (TDM) is synthesized from two molecules of trehalose-6'-monomycolate (TMM) by antigen 85A. We report here a novel enzyme assay using the natural substrate TMM. The novel colorimetric assay is based on the quantification of glucose from the degradation of trehalose, which is the product from catalytic activity of antigen 85A. Using the new assay, K(m) and K(cat) were determined with values of 129.6+/-8.1 microM and 65.4+/-4.1 min(-1), respectively. This novel assay is also suitable for robust high-throughput screening (HTS) for compound library screening against mycolyltransferase (antigen 85A). The assay is significantly faster and more convenient to use than all assays currently in use. The assay has a very low coefficient of variance (0.04) in 96-well plates and shows a Z' factor of 0.67-0.73, indicating the robustness of the assay. In addition, this new assay is highly suitable for the quantification of total TMM of the mycobacterial cell envelope.
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Affiliation(s)
- Ayssar A Elamin
- Department of Genome Analysis, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
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Identification of a stress-induced factor of Corynebacterineae that is involved in the regulation of the outer membrane lipid composition. J Bacteriol 2009; 191:7323-32. [PMID: 19801408 DOI: 10.1128/jb.01042-09] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Corynebacterineae are gram-positive bacteria that possess a true outer membrane composed of mycolic acids and other lipids. Little is known concerning the modulation of mycolic acid composition and content in response to changes in the bacterial environment, especially temperature variations. To address this question, we investigated the function of the Rv3802c gene, a gene conserved in Corynebacterineae and located within a gene cluster involved in mycolic acid biosynthesis. We showed that the Rv3802 ortholog is essential in Mycobacterium smegmatis, while its Corynebacterium glutamicum ortholog, NCgl2775, is not. We provided evidence that the NCgl2775 gene is transcriptionally induced under heat stress conditions, and while the corresponding protein has no detectable activity under normal growth conditions, the increase in its expression triggers an increase in mycolic acid biosynthesis concomitant with a decrease in phospholipid content. We demonstrated that these lipid modifications are part of a larger outer membrane remodeling that occurs in response to exposure to a moderately elevated temperature (42 degrees C). In addition to showing an increase in the ratio of saturated corynomycolates to unsaturated corynomycolates, our results strongly suggested that the balance between mycolic acids and phospholipids is modified inside the outer membrane following a heat challenge. Furthermore, we showed that these lipid modifications help the bacteria to protect against heat damage. The NCgl2775 protein and its orthologs thus appear to be a protein family that plays a role in the regulation of the outer membrane lipid composition of Corynebacterineae under stress conditions. We therefore propose to name this protein family the envelope lipids regulation factor (ElrF) family.
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Triacylglycerol utilization is required for regrowth of in vitro hypoxic nonreplicating Mycobacterium bovis bacillus Calmette-Guerin. J Bacteriol 2009; 191:5037-43. [PMID: 19525349 DOI: 10.1128/jb.00530-09] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mycobacteria store triacylglycerols (TGs) under various stress conditions, such as hypoxia, exposure to nitric oxide, and acidic environments. These stress conditions are known to induce nonreplicating persistence in mycobacteria. The importance of TG accumulation and utilization during regrowth is not clearly understood. Here we specifically determined the levels of accumulated TG and TG lipase activity in Mycobacterium bovis bacillus Calmette-Guerin (BCG) in various different physiological states (logarithmic growth, aerated stationary phase, hypoxia-induced dormancy, and regrowth from dormancy). We found extensive accumulation and degradation of TGs in the bacilli during entry into and exit from hypoxia-induced dormancy, respectively. These processes are accompanied by dynamic appearance and disappearance of intracellular TG lipid particles. The reduction in TG levels coincides with an increase in cellular TG lipase activity in the regrowing bacilli. Tetrahydrolipstatin, an inhibitor of TG lipases, reduces total lipase activity, prevents breakdown of TGs, and blocks the growth of mycobacteria upon resuscitation with air. Our results demonstrate that utilization of TGs is essential for the regrowth of mycobacteria during their exit from the hypoxic nonreplicating state.
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