1
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Phage Display-Derived Peptides and Antibodies for Bacterial Infectious Diseases Therapy and Diagnosis. Molecules 2023; 28:molecules28062621. [PMID: 36985593 PMCID: PMC10052323 DOI: 10.3390/molecules28062621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/01/2023] [Accepted: 03/06/2023] [Indexed: 03/17/2023] Open
Abstract
The emergence of antibiotic-resistant-bacteria is a serious public health threat, which prompts us to speed up the discovery of novel antibacterial agents. Phage display technology has great potential to screen peptides or antibodies with high binding capacities for a wide range of targets. This property is significant in the rapid search for new antibacterial agents for the control of bacterial resistance. In this paper, we not only summarized the recent progress of phage display for the discovery of novel therapeutic agents, identification of action sites of bacterial target proteins, and rapid detection of different pathogens, but also discussed several problems of this technology that must be solved. Breakthrough in these problems may further promote the development and application of phage display technology in the biomedical field in the future.
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2
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Romano K, Hung D. Targeting LPS biosynthesis and transport in gram-negative bacteria in the era of multi-drug resistance. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119407. [PMID: 36543281 PMCID: PMC9922520 DOI: 10.1016/j.bbamcr.2022.119407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 11/09/2022] [Accepted: 11/18/2022] [Indexed: 12/23/2022]
Abstract
Gram-negative bacteria pose a major threat to human health in an era fraught with multi-drug resistant bacterial infections. Despite extensive drug discovery campaigns over the past decades, no new antibiotic target class effective against gram-negative bacteria has become available to patients since the advent of the carbapenems in 1985. Antibiotic discovery efforts against gram-negative bacteria have been hampered by limited intracellular accumulation of xenobiotics, in large part due to the impermeable cell envelope comprising lipopolysaccharide (LPS) in the outer leaflet of the outer membrane, as well as a panoply of efflux pumps. The biosynthesis and transport of LPS are essential to the viability and virulence of most gram-negative bacteria. Thus, both LPS biosynthesis and transport are attractive pathways to target therapeutically. In this review, we summarize the LPS biosynthesis and transport pathways and discuss efforts to find small molecule inhibitors against targets within these pathways.
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Affiliation(s)
- K.P. Romano
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Boston, MA, USA,The Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA
| | - D.T. Hung
- The Broad Institute of MIT and Harvard, Cambridge, MA, USA,Department of Molecular Biology, Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, MA, USA,Department of Genetics, Harvard Medical School, Boston, MA, USA,Corresponding author at: The Broad Institute of MIT and Harvard, Cambridge, MA, USA. (D.T. Hung)
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3
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Ryan MD, Parkes AL, Corbett D, Dickie AP, Southey M, Andersen OA, Stein DB, Barbeau OR, Sanzone A, Thommes P, Barker J, Cain R, Compper C, Dejob M, Dorali A, Etheridge D, Evans S, Faulkner A, Gadouleau E, Gorman T, Haase D, Holbrow-Wilshaw M, Krulle T, Li X, Lumley C, Mertins B, Napier S, Odedra R, Papadopoulos K, Roumpelakis V, Spear K, Trimby E, Williams J, Zahn M, Keefe AD, Zhang Y, Soutter HT, Centrella PA, Clark MA, Cuozzo JW, Dumelin CE, Deng B, Hunt A, Sigel EA, Troast DM, DeJonge BLM. Discovery of Novel UDP- N-Acetylglucosamine Acyltransferase (LpxA) Inhibitors with Activity against Pseudomonas aeruginosa. J Med Chem 2021; 64:14377-14425. [PMID: 34569791 DOI: 10.1021/acs.jmedchem.1c00888] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study describes a novel series of UDP-N-acetylglucosamine acyltransferase (LpxA) inhibitors that was identified through affinity-mediated selection from a DNA-encoded compound library. The original hit was a selective inhibitor of Pseudomonas aeruginosa LpxA with no activity against Escherichia coli LpxA. The biochemical potency of the series was optimized through an X-ray crystallography-supported medicinal chemistry program, resulting in compounds with nanomolar activity against P. aeruginosa LpxA (best half-maximal inhibitory concentration (IC50) <5 nM) and cellular activity against P. aeruginosa (best minimal inhibitory concentration (MIC) of 4 μg/mL). Lack of activity against E. coli was maintained (IC50 > 20 μM and MIC > 128 μg/mL). The mode of action of analogues was confirmed through genetic analyses. As expected, compounds were active against multidrug-resistant isolates. Further optimization of pharmacokinetics is needed before efficacy studies in mouse infection models can be attempted. To our knowledge, this is the first reported LpxA inhibitor series with selective activity against P. aeruginosa.
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Affiliation(s)
- M Dominic Ryan
- X-Biotix Therapeutics, 465 Waverly Oaks Road, Waltham, Massachusetts 02452, United States
| | - Alastair L Parkes
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - David Corbett
- Evotec UK, Anti-infectives, Block 23F, Alderley Park, Cheshire SK10 4TG, U.K
| | - Anthony P Dickie
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Michelle Southey
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Ole A Andersen
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Daniel B Stein
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, 22419 Hamburg, Germany
| | - Olivier R Barbeau
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Angelo Sanzone
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Pia Thommes
- Evotec UK, Anti-infectives, Block 23F, Alderley Park, Cheshire SK10 4TG, U.K
| | - John Barker
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Ricky Cain
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Christel Compper
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Magali Dejob
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Alain Dorali
- Evotec UK, Anti-infectives, Block 23F, Alderley Park, Cheshire SK10 4TG, U.K
| | - Donnya Etheridge
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Sian Evans
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Adele Faulkner
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Elise Gadouleau
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Timothy Gorman
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Denes Haase
- Evotec SE, Manfred Eigen Campus, Essener Bogen 7, 22419 Hamburg, Germany
| | | | - Thomas Krulle
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Xianfu Li
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Christopher Lumley
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Barbara Mertins
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Spencer Napier
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Rajesh Odedra
- Evotec UK, Anti-infectives, Block 23F, Alderley Park, Cheshire SK10 4TG, U.K
| | - Kostas Papadopoulos
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | | | - Kate Spear
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Emily Trimby
- Evotec UK, Anti-infectives, Block 23F, Alderley Park, Cheshire SK10 4TG, U.K
| | - Jennifer Williams
- Evotec UK, Anti-infectives, Block 23F, Alderley Park, Cheshire SK10 4TG, U.K
| | - Michael Zahn
- Evotec, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, U.K
| | - Anthony D Keefe
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Ying Zhang
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Holly T Soutter
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Paolo A Centrella
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Matthew A Clark
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - John W Cuozzo
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | | | - Boer Deng
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Avery Hunt
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Eric A Sigel
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Dawn M Troast
- X-Chem, 100 Beaver Street, Waltham, Massachusetts 02453, United States
| | - Boudewijn L M DeJonge
- X-Biotix Therapeutics, 465 Waverly Oaks Road, Waltham, Massachusetts 02452, United States
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4
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Troudi A, Pagès JM, Brunel JM. Chemical Highlights Supporting the Role of Lipid A in Efficient Biological Adaptation of Gram-Negative Bacteria to External Stresses. J Med Chem 2021; 64:1816-1834. [PMID: 33538159 DOI: 10.1021/acs.jmedchem.0c02185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The outer membrane (OM) of Gram-negative bacteria provides an efficient barrier against external noxious compounds such as antimicrobial agents. Associated with drug target modification, it contributes to the overall failure of chemotherapy. In the complex OM architecture, Lipid A plays an essential role by anchoring the lipopolysaccharide in the membrane and ensuring the spatial organization between lipids, proteins, and sugars. Currently, the targets of almost all antibiotics are intracellularly located and require translocation across membranes. We report herein an integrated view of Lipid A synthesis, membrane assembly, a structure comparison at the molecular structure level of numerous Gram-negative bacterial species, as well as its recent use as a target for original antibacterial molecules. This review paves the way for a new vision of a key membrane component that acts during bacterial adaptation to environmental stresses and for the development of new weapons against microbial resistance to usual antibiotics.
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Affiliation(s)
- Azza Troudi
- UMR-MD1, U1261, Aix Marseille Université, INSERM, SSA, MCT, 13385 Marseille, France.,Laboratory of Microorganisms and Active Biomolecules, Department of Biology, Faculty of Sciences of Tunis, University of Tunis El Manar, Tunis 1008, Tunisia
| | - Jean Marie Pagès
- UMR-MD1, U1261, Aix Marseille Université, INSERM, SSA, MCT, 13385 Marseille, France
| | - Jean Michel Brunel
- UMR-MD1, U1261, Aix Marseille Université, INSERM, SSA, MCT, 13385 Marseille, France
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5
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Han W, Ma X, Balibar CJ, Baxter Rath CM, Benton B, Bermingham A, Casey F, Chie-Leon B, Cho MK, Frank AO, Frommlet A, Ho CM, Lee PS, Li M, Lingel A, Ma S, Merritt H, Ornelas E, De Pascale G, Prathapam R, Prosen KR, Rasper D, Ruzin A, Sawyer WS, Shaul J, Shen X, Shia S, Steffek M, Subramanian S, Vo J, Wang F, Wartchow C, Uehara T. Two Distinct Mechanisms of Inhibition of LpxA Acyltransferase Essential for Lipopolysaccharide Biosynthesis. J Am Chem Soc 2020; 142:4445-4455. [DOI: 10.1021/jacs.9b13530] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wooseok Han
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Xiaolei Ma
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Carl J. Balibar
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | | | - Bret Benton
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Alun Bermingham
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Fergal Casey
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Barbara Chie-Leon
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Min-Kyu Cho
- Novartis Institutes for BioMedical Research, Cambridge, Massachusetts 02139, United States
| | - Andreas O. Frank
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Alexandra Frommlet
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Chi-Min Ho
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Patrick S. Lee
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Min Li
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Andreas Lingel
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Sylvia Ma
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Hanne Merritt
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Elizabeth Ornelas
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Gianfranco De Pascale
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Ramadevi Prathapam
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Katherine R. Prosen
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Dita Rasper
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Alexey Ruzin
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - William S. Sawyer
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Jacob Shaul
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Xiaoyu Shen
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Steven Shia
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Micah Steffek
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Sharadha Subramanian
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Jason Vo
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Feng Wang
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Charles Wartchow
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
| | - Tsuyoshi Uehara
- Novartis Institutes for BioMedical Research, Emeryville, California 94608, United States
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6
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MacNair CR, Tsai CN, Brown ED. Creative targeting of the Gram-negative outer membrane in antibiotic discovery. Ann N Y Acad Sci 2019; 1459:69-85. [PMID: 31762048 DOI: 10.1111/nyas.14280] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/30/2019] [Accepted: 10/31/2019] [Indexed: 12/13/2022]
Abstract
The rising threat of multidrug-resistant Gram-negative bacteria is exacerbated by the scarcity of new antibiotics in the development pipeline. Permeability through the outer membrane remains one of the leading hurdles in discovery efforts. However, the essentiality of a robust outer membrane makes itself an intriguing antimicrobial target. Herein, we review drug discovery efforts targeting the outer membrane and the prospective antimicrobial leads identified.
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Affiliation(s)
- Craig R MacNair
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Caressa N Tsai
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Eric D Brown
- Michael G. DeGroote Institute for Infectious Disease Research, Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
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7
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Zhao L, Hu X, Li Y, Wang Z, Wang X. Construction of a novel Escherichia coli expression system: relocation of lpxA from chromosome to a constitutive expression vector. Appl Microbiol Biotechnol 2019; 103:7177-7189. [PMID: 31317228 DOI: 10.1007/s00253-019-10013-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/22/2019] [Accepted: 07/05/2019] [Indexed: 11/26/2022]
Abstract
The selective marker in the plasmid-based expression system is usually a gene that encodes an antibiotic-resistant protein; therefore, the antibiotic has to add to maintain the plasmid when growing the bacteria. This antibiotic addition would lead to increase of production cost and the environment contamination. In this study, a novel Escherichia coli expression system, the lpxA deletion mutant harboring an lpxA-carrying vector, was developed. To develop this system, three plasmids pCas9Cre, pTF-A-UD, and pRSFCmlpxA were constructed. The plasmid pCas9Cre produces enzymes Cas9, λ-Red, and Cre and can be cured by growing at 42 °C; pTF-A-UD contains several DNA fragments required for deleting the chromosomal lpxA and can be cured by adding isopropyl-D-thiogalactopyranoside; pRSFCmlpxA contains the lpxA mutant lpxA123 and CamR. When E. coli were transformed with these three plasmids, the chromosomal lpxA and the CamR in pRSFCmlpxA can be efficiently removed, resulting in an E. coli lpxA mutant harboring pRSFlpxA. The lpxA is essential for the growth of E. coli; its relocation from chromosome to a constitutive expression vector is an ideal strategy to maintain the vector without antibiotic addition. The lpxA123 in pRSFlpxA can complement the deletion of the chromosomal lpxA and provide a strong selective pressure to maintain the plasmid pRSFlpxA. This study provides an experimental evidence that this novel expression system is convenient and efficient to use and can be used to improve L-threonine biosynthesis in the wild type E. coli MG1655 and an L-threonine producing E. coli TWF006.
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Affiliation(s)
- Lei Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Ye Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Zhen Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.
- International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China.
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
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8
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Structure guided design of an antibacterial peptide that targets UDP-N-acetylglucosamine acyltransferase. Sci Rep 2019; 9:3947. [PMID: 30850651 PMCID: PMC6408518 DOI: 10.1038/s41598-019-40418-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 02/14/2019] [Indexed: 11/08/2022] Open
Abstract
UDP-N-acetylglucosamine (UDP-GlcNAc) acyltransferase (LpxA) catalyzes the first step of lipid A biosynthesis, the transfer of an R-3-hydroxyacyl chain from its acyl carrier protein (ACP) to the 3-OH group of UDP-GlcNAc. Essential in the growth of Gram-negative bacteria, LpxA is a logical target for antibiotics design. A pentadecapeptide (Peptide 920) with high affinity towards LpxA was previously identified in a phage display library. Here we created a small library of systematically designed peptides with the length of four to thirteen amino acids using Peptide 920 as a scaffold. The concentrations of these peptides at which 50% of LpxA is inhibited (IC50) range from 50 nM to >100 μM. We determined the crystal structure of E. coli LpxA in a complex with a potent inhibitor. LpxA-inhibitor interaction, solvent model and all contributing factors to inhibitor efficacy were well resolved. The peptide primarily occludes the ACP binding site of LpxA. Interactions between LpxA and the inhibitor are different from those in the structure of Peptide 920. The inhibitory peptide library and the crystal structure of inhibitor-bound LpxA described here may further assist in the rational design of inhibitors with antimicrobial activity that target LpxA and potentially other acyltransferases.
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9
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González-Bello C. The Inhibition of Lipid A Biosynthesis-The Antidote Against Superbugs? ADVANCED THERAPEUTICS 2018. [DOI: 10.1002/adtp.201800117] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Concepción González-Bello
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS); Departamento de Química Orgánica; Universidade de Santiago de Compostela; calle Jenaro de la Fuente s/n 15782 Santiago de Compostela Spain
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10
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Kim S, Yoon H, Ryu S. New virulence factor CSK29544_02616 as LpxA binding partner in Cronobacter sakazakii. Sci Rep 2018; 8:835. [PMID: 29339761 PMCID: PMC5770445 DOI: 10.1038/s41598-018-19306-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 12/29/2017] [Indexed: 01/13/2023] Open
Abstract
Cronobacter sakazakii is an opportunistic pathogen that can cause meningitis and necrotizing enterocolitis in premature infants, but its virulence determinants remain largely unknown. In this study, a transposon-mediated random-mutant library of C. sakazakii was used to identify new virulence factors. Compared to wild-type bacteria, a mutant lacking CSK29544_02616 (referred to as labp) was defective in invasion into intestinal epithelial cells (by at least 1000-fold) and showed less phagocytosis by macrophages (by at least 50-fold). The lack of labp in C. sakazakii changed the profile of outer membrane proteins, decreased the production of lipopolysaccharides, and increased the production of membrane phospholipids. Bacterial physiological characteristics including surface hydrophobicity and motility were also altered in the absence of labp, presumably because of changes in the bacterial-envelope structure. To systematically determine the role of labp, ligand fishing was conducted using Labp as a bait, which revealed LpxA as a binding partner of Labp. LpxA is UDP-N-acetylglucosamine (GlcNAc) acyltransferase, the first enzyme in the pathway of lipid A biosynthesis. Labp increased the enzymatic activity of LpxA without influencing lpxA expression. Considering multifaceted roles of lipopolysaccharides in virulence regulation, Labp is a novel virulence factor that promotes the production of lipid A by LpxA in Cronobacter.
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Affiliation(s)
- Seongok Kim
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, and Center for Food and Bioconvergence, Seoul National University, Seoul, 08826, Korea.,Department of Molecular Science and Technology, Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, 16499, South Korea
| | - Hyunjin Yoon
- Department of Molecular Science and Technology, Department of Applied Chemistry and Biological Engineering, Ajou University, Suwon, 16499, South Korea.
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Research Institute for Agriculture and Life Sciences, and Center for Food and Bioconvergence, Seoul National University, Seoul, 08826, Korea.
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11
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Zhou P, Zhao J. Structure, inhibition, and regulation of essential lipid A enzymes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:1424-1438. [PMID: 27940308 DOI: 10.1016/j.bbalip.2016.11.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/28/2016] [Accepted: 11/30/2016] [Indexed: 10/20/2022]
Abstract
The Raetz pathway of lipid A biosynthesis plays a vital role in the survival and fitness of Gram-negative bacteria. Research efforts in the past three decades have identified individual enzymes of the pathway and have provided a mechanistic understanding of the action and regulation of these enzymes at the molecular level. This article reviews the discovery, biochemical and structural characterization, and regulation of the essential lipid A enzymes, as well as continued efforts to develop novel antibiotics against Gram-negative pathogens by targeting lipid A biosynthesis. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop.
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Affiliation(s)
- Pei Zhou
- Department of Biochemistry, Duke University Medical Center, Research Drive, DUMC 3711, Durham, NC 27710, USA.
| | - Jinshi Zhao
- Department of Biochemistry, Duke University Medical Center, Research Drive, DUMC 3711, Durham, NC 27710, USA
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12
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Joo SH. Lipid A as a Drug Target and Therapeutic Molecule. Biomol Ther (Seoul) 2015; 23:510-6. [PMID: 26535075 PMCID: PMC4624066 DOI: 10.4062/biomolther.2015.117] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 09/22/2015] [Accepted: 10/05/2015] [Indexed: 11/05/2022] Open
Abstract
In this review, lipid A, from its discovery to recent findings, is presented as a drug target and therapeutic molecule. First, the biosynthetic pathway for lipid A, the Raetz pathway, serves as a good drug target for antibiotic development. Several assay methods used to screen for inhibitors of lipid A synthesis will be presented, and some of the promising lead compounds will be described. Second, utilization of lipid A biosynthetic pathways by various bacterial species can generate modified lipid A molecules with therapeutic value.
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Affiliation(s)
- Sang Hoon Joo
- Laboratory of Biochemistry, College of Pharmacy, Catholic University of Daegu, Gyeongbuk 38430, Republic of Korea
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13
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Jenkins RJ, Heslip KA, Meagher JL, Stuckey JA, Dotson GD. Structural basis for the recognition of peptide RJPXD33 by acyltransferases in lipid A biosynthesis. J Biol Chem 2014; 289:15527-35. [PMID: 24742680 PMCID: PMC4140908 DOI: 10.1074/jbc.m114.564278] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 04/15/2014] [Indexed: 01/28/2023] Open
Abstract
UDP-N-acetylglucosamine acyltransferase (LpxA) and UDP-3-O-(acyl)-glucosamine acyltransferase (LpxD) constitute the essential, early acyltransferases of lipid A biosynthesis. Recently, an antimicrobial peptide inhibitor, RJPXD33, was identified with dual affinity for LpxA and LpxD. To gain a fundamental understanding of the molecular basis of inhibitor binding, we determined the crystal structure of LpxA from Escherichia coli in complex with RJPXD33 at 1.9 Å resolutions. Our results suggest that the peptide binds in a unique modality that mimics (R)-β-hydroxyacyl pantetheine binding to LpxA and displays how the peptide binds exclusive of the native substrate, acyl-acyl carrier protein. Acyltransferase binding studies with photo-labile RJPXD33 probes and truncations of RJPXD33 validated the structure and provided fundamental insights for future design of small molecule inhibitors. Overlay of the LpxA-RJPXD33 structure with E. coli LpxD identified a complementary peptide binding pocket within LpxD and serves as a model for further biochemical characterization of RJPXD33 binding to LpxD.
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Affiliation(s)
- Ronald J Jenkins
- From the Department of Medicinal Chemistry, College of Pharmacy, and
| | - Kyle A Heslip
- From the Department of Medicinal Chemistry, College of Pharmacy, and
| | - Jennifer L Meagher
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109
| | - Jeanne A Stuckey
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109
| | - Garry D Dotson
- From the Department of Medicinal Chemistry, College of Pharmacy, and
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14
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Abstract
Lipopolysaccharide molecules represent a unique family of glycolipids based on a highly conserved lipid moiety known as lipid A. These molecules are produced by most gram-negative bacteria, in which they play important roles in the integrity of the outer-membrane permeability barrier and participate extensively in host-pathogen interplay. Few bacteria contain lipopolysaccharide molecules composed only of lipid A. In most forms, lipid A is glycosylated by addition of the core oligosaccharide that, in some bacteria, provides an attachment site for a long-chain O-antigenic polysaccharide. The complexity of lipopolysaccharide structures is reflected in the processes used for their biosynthesis and export. Rapid growth and cell division depend on the bacterial cell's capacity to synthesize and export lipopolysaccharide efficiently and in large amounts. We review recent advances in those processes, emphasizing the reactions that are essential for viability.
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Affiliation(s)
- Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada;
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15
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Rao C V S, De Waelheyns E, Economou A, Anné J. Antibiotic targeting of the bacterial secretory pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1762-83. [PMID: 24534745 DOI: 10.1016/j.bbamcr.2014.02.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/27/2014] [Accepted: 02/06/2014] [Indexed: 02/06/2023]
Abstract
Finding new, effective antibiotics is a challenging research area driven by novel approaches required to tackle unconventional targets. In this review we focus on the bacterial protein secretion pathway as a target for eliminating or disarming pathogens. We discuss the latest developments in targeting the Sec-pathway for novel antibiotics focusing on two key components: SecA, the ATP-driven motor protein responsible for driving preproteins across the cytoplasmic membrane and the Type I signal peptidase that is responsible for the removal of the signal peptide allowing the release of the mature protein from the membrane. We take a bird's-eye view of other potential targets in the Sec-pathway as well as other Sec-dependent or Sec-independent protein secretion pathways as targets for the development of novel antibiotics. This article is part of a Special Issue entitled: Protein trafficking and secretion in bacteria. Guest Editors: Anastassios Economou and Ross Dalbey.
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Affiliation(s)
- Smitha Rao C V
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium.
| | - Evelien De Waelheyns
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium.
| | - Anastassios Economou
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium; Institute of Molecular Biology and Biotechnology, FORTH, University of Crete, P.O. Box 1385, GR-711 10 Iraklio, Crete, Greece; Department of Biology, University of Crete, P.O. Box 1385, GR-71110 Iraklio, Crete, Greece.
| | - Jozef Anné
- Laboratory of Molecular Bacteriology, Rega Institute, Department of Microbiology and Immunology, KU Leuven, O&N1, 6th floor, Herestraat 49, P.O. Box 1037, B-3000 Leuven, Belgium.
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16
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Shapiro AB, Ross PL, Gao N, Livchak S, Kern G, Yang W, Andrews B, Thresher J. A high-throughput-compatible fluorescence anisotropy-based assay for competitive inhibitors of Escherichia coli UDP-N-acetylglucosamine acyltransferase (LpxA). ACTA ACUST UNITED AC 2012; 18:341-7. [PMID: 23015018 DOI: 10.1177/1087057112462062] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
LpxA, the first enzyme in the biosynthetic pathway for the Lipid A component of the outer membrane lipopolysaccharide in Gram-negative bacteria, is a potential target for novel antibacterial drug discovery. A fluorescence polarization assay was developed to facilitate high-throughput screening for competitive inhibitors of LpxA. The assay detects displacement of a fluorescently labeled peptide inhibitor, based on the previously reported inhibitor peptide 920, by active site ligands. The affinity of the fluorescent ligand was increased ~10-fold by acyl carrier protein (ACP). Competition with peptide binding was observed with UDP-N-acetylglucosamine (IC(50) ~6 mM), UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine (IC(50) ~200 nM), and DL-3-hydroxymyristic acid (IC(50) ~50 µM) and peptide 920 (IC(50) ~600 nM). The IC(50)s were not significantly affected by the presence of ACP.
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17
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Abstract
There are a number of genetic tools available for studying Francisella tularensis, the etiological agent of tularemia; however, there is no effective inducible or repressible gene expression system. Here, we describe inducible and repressible gene expression systems for F. tularensis based on the Tet repressor, TetR. For the inducible system, a tet operator sequence was cloned into a modified F. tularensis groESL promoter sequence and carried in a plasmid that constitutively expressed TetR. To monitor regulation the luminescence operon, luxCDABE, was cloned under the hybrid Francisella tetracycline-regulated promoter (FTRp), and transcription was initiated with addition of anhydrotetracycline (ATc), which binds TetR and alleviates TetR association with tetO. Expression levels measured by luminescence correlated with ATc inducer concentrations ranging from 20 to 250 ng ml(-1). In the absence of ATc, luminescence was below the level of detection. The inducible system was also functional during the infection of J774A.1 macrophages, as determined by both luminescence and rescue of a mutant strain with an intracellular growth defect. The repressible system consists of FTRp regulated by a reverse TetR mutant (revTetR), TetR r1.7. Using this system with the lux reporter, the addition of ATc resulted in decreased luminescence, while in the absence of ATc the level of luminescence was not significantly different from that of a construct lacking TetR r1.7. Utilizing both systems, the essentiality of SecA, the protein translocase ATPase, was confirmed, establishing that they can effectively regulate gene expression. These two systems will be invaluable in exploring F. tularensis protein function.
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18
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Jenkins RJ, Dotson GD. Dual targeting antibacterial peptide inhibitor of early lipid A biosynthesis. ACS Chem Biol 2012; 7:1170-7. [PMID: 22530734 DOI: 10.1021/cb300094a] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
UDP-3-O-(R-3-hydroxyacyl)GlcN N-acyltransferase (LpxD) has been shown to be essential to survival of lipid A producing Gram-negative bacteria. In this study, LpxD-binding peptides 12 amino acids in length were identified from a phage-bound random peptide library screen. Three peptides displayed antibacterial activity when expressed intracellularly, one of which (RJPXD33) represented 15% of the total hits. RJPXD33 binds to E. coli LpxD with a K(d) of 6 μM and is competitive with R-3-hydroxymyristoyl-ACP binding. RJPXD33 can be C-terminally fused in vivo with thioredoxin or N-terminally modified in vitro with β-alanyl-fluorescein and maintain LpxD binding. The latter was used to develop an LpxD fluorescent binding assay used to evaluate unlabeled ligands and is amenable to small molecule library screening. Furthermore, RJPXD33 also binds to and inhibits E. coli UDP-N-acetylglucosamine acyltransferase (LpxA) with a K(d) of 20 μM, unearthing the possibility for the development of small molecule, dual-binding LpxA/LpxD inhibitors as novel antimicrobials.
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Affiliation(s)
- Ronald J. Jenkins
- Department of Medicinal Chemistry,
College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Garry D. Dotson
- Department of Medicinal Chemistry,
College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
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19
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Bhattarai SR, Yoo SY, Lee SW, Dean D. Engineered phage-based therapeutic materials inhibit Chlamydia trachomatis intracellular infection. Biomaterials 2012; 33:5166-74. [PMID: 22494890 DOI: 10.1016/j.biomaterials.2012.03.054] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 03/15/2012] [Indexed: 12/25/2022]
Abstract
Developing materials that are effective against sexually transmitted pathogens such as Chlamydia trachomatis (Ct) and HIV-1 is challenging both in terms of material selection and improving bio-membrane and cellular permeability at desired mucosal sites. Here, we engineered the prokaryotic bacterial virus (M13 phage) carrying two functional peptides, integrin binding peptide (RGD) and a segment of the polymorphic membrane protein D (PmpD) from Ct, as a phage-based material that can ameliorate Ct infection. Ct is a globally prevalent human pathogen for which there are no effective vaccines or microbicides. We show that engineered phage stably express both RGD motifs and Ct peptides and traffic intracellularly and into the lumen of the inclusion in which the organism resides within the host cell. Engineered phage were able to significantly reduce Ct infection in both HeLa and primary endocervical cells compared with Ct infection alone. Polyclonal antibodies raised against PmpD and co-incubated with constructs prior to infection did not alter the course of infection, indicating that PmpD is responsible for the observed decrease in Ct infection. Our results suggest that phage-based design approaches to vector delivery that overcome mucosal cellular barriers may be effective in preventing Ct and other sexually transmitted pathogens.
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Affiliation(s)
- Shanta Raj Bhattarai
- Center for Immunobiology and Vaccine Development, Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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20
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Page MGP. The role of the outer membrane of Gram-negative bacteria in antibiotic resistance: Ajax' shield or Achilles' heel? Handb Exp Pharmacol 2012:67-86. [PMID: 23090596 DOI: 10.1007/978-3-642-28951-4_5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There has been an enormous increase in our knowledge of the fundamental steps in the biosynthesis and assembly of the outer membrane of Gram-negative bacteria. Lipopolysaccharide is a major component of the outer membrane of Gram-negative bacteria as is peptidoglycan. Porins, efflux pumps and other transport proteins of the outer membrane are also present. It is clear that there are numerous essential proteins that have the potential to be targets for novel antimicrobial agents. Progress, however, has been slow. Much of the emphasis has been on cytoplasmic processes that were better understood earlier on, but have the drawback that two penetration barriers, with different permeability properties, have to be crossed. With the increased understanding of the late-stage events occurring in the periplasm, it may be possible to shift focus to these more accessible targets. Nevertheless, getting drugs across the outer membrane will remain a challenge to the ingenuity of the medicinal chemist.
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21
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Traffic jam at the bacterial sec translocase: targeting the SecA nanomotor by small-molecule inhibitors. ACTA ACUST UNITED AC 2011; 18:685-98. [PMID: 21700205 DOI: 10.1016/j.chembiol.2011.04.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 04/27/2011] [Accepted: 04/28/2011] [Indexed: 11/20/2022]
Abstract
The rapid rise of drug-resistant bacteria is one of the most serious unmet medical needs facing the world. Despite this increasing problem of antibiotic resistance, the number of different antibiotics available for the treatment of serious infections is dwindling. Therefore, there is an urgent need for new antibacterial drugs, preferably with novel modes of action to potentially avoid cross-resistance with existing antibacterial agents. In recent years, increasing attention has been paid to bacterial protein secretion as a potential antibacterial target. Among the different protein secretion pathways that are present in bacterial pathogens, the general protein secretory (Sec) pathway is widely considered as an attractive target for antibacterial therapy. One of the key components of the Sec pathway is the peripheral membrane ATPase SecA, which provides the energy for the translocation of preproteins across the bacterial cytoplasmic membrane. In this review, we will provide an overview of research efforts on the discovery and development of small-molecule SecA inhibitors. Furthermore, recent advances on the structure and function of SecA and their potential impact on antibacterial drug discovery will be discussed.
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22
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Novikova LA, Faletrov YV, Kovaleva IE, Mauersberger S, Luzikov VN, Shkumatov VM. From structure and functions of steroidogenic enzymes to new technologies of gene engineering. BIOCHEMISTRY (MOSCOW) 2010; 74:1482-504. [DOI: 10.1134/s0006297909130057] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Robins LI, Williams AH, Raetz CRH. Structural basis for the sugar nucleotide and acyl-chain selectivity of Leptospira interrogans LpxA. Biochemistry 2009; 48:6191-201. [PMID: 19456129 DOI: 10.1021/bi900629e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The first step of lipid A biosynthesis is catalyzed by LpxA in Escherichia coli (EcLpxA), an acyltransferase selective for UDP-GlcNAc and R-3-hydroxymyristoyl-acyl carrier protein (ACP). Leptospira interrogans LpxA (LiLpxA) is extremely selective for R-3-hydroxylauroyl-ACP and an analogue of UDP-GlcNAc, designated UDP-GlcNAc3N, in which NH(2) replaces the GlcNAc 3-OH group. EcLpxA does not discriminate between UDP-GlcNAc and UDP-GlcNAc3N; however, E. coli does not make UDP-GlcNAc3N. With LiLpxA, R-3-hydroxylauroyl-methylphosphopantetheine efficiently substitutes for R-3-hydroxylauroyl-ACP. We now present crystal structures of free LiLpxA and its complexes with its product UDP-3-N-(R-3-hydroxylauroyl)-GlcNAc3N and with its substrate R-3-hydroxylauroyl-methylphosphopantetheine. The positions of the acyl chains of the R-3-hydroxylauroyl-methylphosphopantetheine and the UDP-3-N-(R-3-hydroxylauroyl)-GlcNAc3N are almost identical and are similar to that of the acyl chain in the EcLpxA/UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc complex. The selectivity of LiLpxA for UDP-GlcNAc3N may be explained by the orientation of the backbone carbonyl group of Q68, which differs by approximately 82 degrees from the corresponding Q73 carbonyl group in EcLpxA. This arrangement provides an extra hydrogen-bond acceptor for the 3-NH(2) group of UDP-GlcNAc3N in LiLpxA. The R-3-hydroxylauroyl selectivity of LiLpxA is explained by the position of the K171 side chain, which limits the length of the acyl-chain-binding groove. Our results support the role of LiLpxA H120 (which corresponds to EcLpxA H125) as the catalytic base and provide the first structural information about the orientation of the phosphopantetheine moiety during LpxA catalysis.
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Affiliation(s)
- Lori I Robins
- Department of Biochemistry, Duke University Medical Center, Box 3711, Durham, North Carolina 27710, USA
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Goh S, Boberek JM, Nakashima N, Stach J, Good L. Concurrent growth rate and transcript analyses reveal essential gene stringency in Escherichia coli. PLoS One 2009; 4:e6061. [PMID: 19557168 PMCID: PMC2698124 DOI: 10.1371/journal.pone.0006061] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Accepted: 06/02/2009] [Indexed: 01/29/2023] Open
Abstract
Background Genes essential for bacterial growth are of particular scientific interest. Many putative essential genes have been identified or predicted in several species, however, little is known about gene expression requirement stringency, which may be an important aspect of bacterial physiology and likely a determining factor in drug target development. Methodology/Principal Findings Working from the premise that essential genes differ in absolute requirement for growth, we describe silencing of putative essential genes in E. coli to obtain a titration of declining growth rates and transcript levels by using antisense peptide nucleic acids (PNA) and expressed antisense RNA. The relationship between mRNA decline and growth rate decline reflects the degree of essentiality, or stringency, of an essential gene, which is here defined by the minimum transcript level for a 50% reduction in growth rate (MTL50). When applied to four growth essential genes, both RNA silencing methods resulted in MTL50 values that reveal acpP as the most stringently required of the four genes examined, with ftsZ the next most stringently required. The established antibacterial targets murA and fabI were less stringently required. Conclusions RNA silencing can reveal stringent requirements for gene expression with respect to growth. This method may be used to validate existing essential genes and to quantify drug target requirement.
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Affiliation(s)
- Shan Goh
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
- Department of Pathology and Infectious Diseases, Royal Veterinary College, University of London, London, United Kingdom
| | - Jaroslaw M. Boberek
- Department of Pathology and Infectious Diseases, Royal Veterinary College, University of London, London, United Kingdom
| | - Nobutaka Nakashima
- Research Institute of Genome-based biofactory, Toyohira-Ku, Sapporo, Japan
| | - Jem Stach
- School of Biology, University of Newcastle, Newcastle upon Tyne, United Kingdom
| | - Liam Good
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
- Department of Pathology and Infectious Diseases, Royal Veterinary College, University of London, London, United Kingdom
- * E-mail:
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25
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Williams AH, Raetz CRH. Structural basis for the acyl chain selectivity and mechanism of UDP-N-acetylglucosamine acyltransferase. Proc Natl Acad Sci U S A 2007; 104:13543-50. [PMID: 17698807 PMCID: PMC1959417 DOI: 10.1073/pnas.0705833104] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
UDP-N-acetylglucosamine (UDP-GlcNAc) acyltransferase (LpxA) catalyzes the first step of lipid A biosynthesis, the reversible transfer of the R-3-hydroxyacyl chain from R-3-hydroxyacyl acyl carrier protein to the glucosamine 3-OH group of UDP-GlcNAc. Escherichia coli LpxA is highly selective for R-3-hydroxymyristate. The crystal structure of the E. coli LpxA homotrimer, determined previously in the absence of lipid substrates or products, revealed that LpxA contains an unusual, left-handed parallel beta-helix fold. We have now solved the crystal structures of E. coli LpxA with the bound product UDP-3-O-(R-3-hydroxymyristoyl)-GlcNAc at a resolution of 1.74 A and with bound UDP-3-O-(R-3-hydroxydecanoyl)-GlcNAc at 1.85 A. The structures of these complexes are consistent with the catalytic mechanism deduced by mutagenesis and with a recent 3.0-A structure of LpxA with bound UDP-GlcNAc. Our structures show how LpxA selects for 14-carbon R-3-hydroxyacyl chains and reveal two modes of UDP binding.
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Affiliation(s)
- Allison H. Williams
- Department of Biochemistry, Duke University Medical Center, Box 3711 DUMC, Durham, NC 27710
| | - Christian R. H. Raetz
- Department of Biochemistry, Duke University Medical Center, Box 3711 DUMC, Durham, NC 27710
- *To whom correspondence should be addressed. E-mail:
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26
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Kongsuwan K, Josh P, Picault MJ, Wijffels G, Dalrymple B. The plasmid RK2 replication initiator protein (TrfA) binds to the sliding clamp beta subunit of DNA polymerase III: implication for the toxicity of a peptide derived from the amino-terminal portion of 33-kilodalton TrfA. J Bacteriol 2006; 188:5501-9. [PMID: 16855240 PMCID: PMC1540049 DOI: 10.1128/jb.00231-06] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The broad-host-range plasmid RK2 is capable of replication and stable maintenance within a wide range of gram-negative bacterial hosts. It encodes the essential replication initiation protein TrfA, which binds to the host initiation protein, DnaA, at the plasmid origin of replication (oriV). There are two versions of the TrfA protein, 44 and 33 kDa, resulting from alternate in-frame translational starts. We have shown that the smaller protein, TrfA-33, and its 64-residue amino-terminal peptide (designated T1) physically interact with the Escherichia coli beta sliding clamp (beta(2)). This interaction appears to be mediated through a QLSLF peptide motif located near the amino-terminal end of TrfA-33 and T1, which is identical to the previously described eubacterial clamp-binding consensus motif. T1 forms a stable complex with beta(2) and was found to inhibit plasmid RK2 replication in vitro. This specific interaction between T1 and beta(2) and the ability of T1 to block DNA replication have implications for the previously reported cell lethality caused by overproduction of T1. The toxicity of T1 was suppressed when wild-type T1 was replaced with mutant T1, carrying an LF deletion in the beta-binding motif. Previously, T1 toxicity has been shown to be suppressed by Hda, an intermediate regulatory protein which helps prevent over-initiation in E. coli through its interaction with the initiator protein, DnaA, and beta(2). Our results support a model in which T1 toxicity is caused by T1 binding to beta(2), especially when T1 is overexpressed, preventing beta(2) from interacting with host replication proteins such as Hda during the early events of chromosome replication.
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Affiliation(s)
- Kritaya Kongsuwan
- CSIRO Livestock Industries, Queensland Bioscience Precinct, 306 Carmody Road, St Lucia QLD 4067, Australia.
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27
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Williams AH, Immormino RM, Gewirth DT, Raetz CRH. Structure of UDP-N-acetylglucosamine acyltransferase with a bound antibacterial pentadecapeptide. Proc Natl Acad Sci U S A 2006; 103:10877-82. [PMID: 16835299 PMCID: PMC1544142 DOI: 10.1073/pnas.0604465103] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
UDP-GlcNAc acyltransferase (LpxA) catalyzes the first step of lipid A biosynthesis, the transfer of the R-3-hydroxyacyl chain from R-3-hydroxyacyl acyl carrier protein (ACP) to the glucosamine 3-OH group of UDP-GlcNAc. LpxA is essential for the growth of Escherichia coli and related Gram-negative bacteria. The crystal structure of the E. coli LpxA homotrimer, determined previously at 2.6 A in the absence of substrates or inhibitors, revealed that LpxA contains an unusual, left-handed parallel beta-helix fold. We now present the crystal structure at 1.8 A resolution of E. coli LpxA in a complex with a pentadecapeptide, peptide 920. Three peptides, each of which adopts a beta-hairpin conformation, are bound per LpxA trimer. The peptides are located at the interfaces of adjacent subunits in the vicinity of the three active sites. Each peptide interacts with residues from both adjacent subunits. Peptide 920 is a potent inhibitor of E. coli LpxA (Ki = 50 nM). It is competitive with respect to acyl-ACP but not UDP-GlcNAc. The compact beta-turn structure of peptide 920 bound to LpxA may open previously uncharacterized approaches to the rational design of LpxA inhibitors with antibiotic activity.
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Affiliation(s)
- Allison H. Williams
- *Department of Biochemistry, Duke University Medical Center, Box 3711 DUMC, Durham, NC 27710; and
| | - Robert M. Immormino
- *Department of Biochemistry, Duke University Medical Center, Box 3711 DUMC, Durham, NC 27710; and
| | - Daniel T. Gewirth
- *Department of Biochemistry, Duke University Medical Center, Box 3711 DUMC, Durham, NC 27710; and
- Hauptman-Woodward Medical Research Institute, 700 Ellicott Street, Buffalo, NY 14203
| | - Christian R. H. Raetz
- *Department of Biochemistry, Duke University Medical Center, Box 3711 DUMC, Durham, NC 27710; and
- To whom correspondence should be addressed. E-mail:
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