1251
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Walsh CT, Fischbach MA. Natural products version 2.0: connecting genes to molecules. J Am Chem Soc 2010; 132:2469-93. [PMID: 20121095 DOI: 10.1021/ja909118a] [Citation(s) in RCA: 337] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Natural products have played a prominent role in the history of organic chemistry, and they continue to be important as drugs, biological probes, and targets of study for synthetic and analytical chemists. In this Perspective, we explore how connecting Nature's small molecules to the genes that encode them has sparked a renaissance in natural product research, focusing primarily on the biosynthesis of polyketides and non-ribosomal peptides. We survey monomer biogenesis, coupling chemistries from templated and non-templated pathways, and the broad set of tailoring reactions and hybrid pathways that give rise to the diverse scaffolds and functionalization patterns of natural products. We conclude by considering two questions: What would it take to find all natural product scaffolds? What kind of scientists will be studying natural products in the future?
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Affiliation(s)
- Christopher T Walsh
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
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1252
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Gronenberg LS, Kahne D. Development of an activity assay for discovery of inhibitors of lipopolysaccharide transport. J Am Chem Soc 2010; 132:2518-9. [PMID: 20136079 DOI: 10.1021/ja910361r] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The outer membrane of gram-negative bacteria contains an outer leaflet composed of lipopolysaccharide (LPS) that is transported to this location by a pathway that is essential for viability. It has been suggested that inhibitors of this pathway could be useful antibiotics. Herein we reconstitute the activity of the ATPase component (LptB) of the ABC transporter that initiates LPS transport and assembly. We developed a high-throughput assay and screened a library of kinase inhibitors against LptB. We identified two classes of ATP-competitive inhibitors. These are the first inhibitors of the ATPase component of any bacterial ABC transporter. The small-molecule inhibitors will be very useful tools for further biochemical studies of the proteins involved in LPS transport and assembly.
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Affiliation(s)
- Luisa S Gronenberg
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 01238, USA
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1253
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Bauer RA, Wurst JM, Tan DS. Expanding the range of 'druggable' targets with natural product-based libraries: an academic perspective. Curr Opin Chem Biol 2010; 14:308-14. [PMID: 20202892 PMCID: PMC2878877 DOI: 10.1016/j.cbpa.2010.02.001] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 02/02/2010] [Indexed: 01/25/2023]
Abstract
Existing drugs address a relatively narrow range of biological targets. As a result, libraries of drug-like molecules have proven ineffective against a variety of challenging targets, such as protein-protein interactions, nucleic acid complexes, and antibacterial modalities. In contrast, natural products are known to be effective at modulating such targets, and new libraries are being developed based on underrepresented scaffolds and regions of chemical space associated with natural products. This has led to several recent successes in identifying new chemical probes that address these challenging targets.
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Affiliation(s)
- Renato A. Bauer
- Tri-Institutional Training Program in Chemical Biology, Memorial Sloan–Kettering Cancer Center, 1275 York Ave, Box 422, New York, NY 10065, USA
| | - Jacqueline M. Wurst
- Tri-Institutional Training Program in Chemical Biology, Memorial Sloan–Kettering Cancer Center, 1275 York Ave, Box 422, New York, NY 10065, USA
| | - Derek S. Tan
- Tri-Institutional Training Program in Chemical Biology, Memorial Sloan–Kettering Cancer Center, 1275 York Ave, Box 422, New York, NY 10065, USA
- Molecular Pharmacology & Chemistry Program and Tri-Institutional Research Program, Memorial Sloan–Kettering Cancer Center, 1275 York Ave, Box 422, New York, NY 10065, USA
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1254
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MacLean RC, Hall AR, Perron GG, Buckling A. The population genetics of antibiotic resistance: integrating molecular mechanisms and treatment contexts. Nat Rev Genet 2010; 11:405-14. [PMID: 20479772 DOI: 10.1038/nrg2778] [Citation(s) in RCA: 156] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Despite efforts from a range of disciplines, our ability to predict and combat the evolution of antibiotic resistance in pathogenic bacteria is limited. This is because resistance evolution involves a complex interplay between the specific drug, bacterial genetics and both natural and treatment ecology. Incorporating details of the molecular mechanisms of drug resistance and ecology into evolutionary models has proved useful in predicting the dynamics of resistance evolution. However, putting these models to practical use will require extensive collaboration between mathematicians, molecular biologists, evolutionary ecologists and clinicians.
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Affiliation(s)
- R Craig MacLean
- Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
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1255
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Patterson LD, Miller MJ. Enzymatic deprotection of the cephalosporin 3'-acetoxy group using Candida antarctica lipase B. J Org Chem 2010; 75:1289-92. [PMID: 20099862 DOI: 10.1021/jo902406b] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cephalosporins remain one of the most important classes of antibiotics. A useful site for derivatization involves generation of and chemistry at the 3'-hydroxymethyl position. While 3'-acetoxymethyl-substituted cephalosporins are readily available, deacetylation to access the free 3'-hydroxymethyl group is problematic when the carboxylic acid is protected as an ester. Herein we report that this important transformation has been efficiently accomplished using Candida antarctica lipase B. Although this transformation is difficult to carry out using chemical methods, the enzymatic deacetylation has been successful on gram scale, when the cephalosporin is protected as either the benzhydryl or tert-butyl esters and on the corresponding sulfoxide and sulfone of the tert-butyl ester.
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Affiliation(s)
- Leslie D Patterson
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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1256
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Oelschlaeger P, Ai N, Duprez KT, Welsh WJ, Toney JH. Evolving carbapenemases: can medicinal chemists advance one step ahead of the coming storm? J Med Chem 2010; 53:3013-27. [PMID: 20121112 DOI: 10.1021/jm9012938] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter Oelschlaeger
- Chemistry Department and Center for Macromolecular Modeling and Materials Design, California State Polytechnic University, Pomona, California, USA.
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1257
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Cussiol JRR, Alegria TGP, Szweda LI, Netto LES. Ohr (organic hydroperoxide resistance protein) possesses a previously undescribed activity, lipoyl-dependent peroxidase. J Biol Chem 2010; 285:21943-50. [PMID: 20463026 DOI: 10.1074/jbc.m110.117283] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Ohr (organic hydroperoxide resistance) family of 15-kDa Cys-based, thiol-dependent peroxidases is central to the bacterial response to stress induced by organic hydroperoxides but not by hydrogen peroxide. Ohr has a unique three-dimensional structure and requires dithiols, but not monothiols, to support its activity. However, the physiological reducing system of Ohr has not yet been identified. Here we show that lipoylated enzymes present in the bacterial extracts of Xylella fastidiosa interacted physically and functionally with this Cys-based peroxidase, whereas thioredoxin and glutathione systems failed to support Ohr peroxidase activity. Furthermore, we could reconstitute in vitro three lipoyl-dependent systems as the Ohr physiological reducing systems. We also showed that OsmC from Escherichia coli, an orthologue of Ohr from Xylella fastidiosa, is specifically reduced by lipoyl-dependent systems. These results represent the first description of a Cys-based peroxidase that is directly reduced by lipoylated enzymes.
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Affiliation(s)
- José R R Cussiol
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociencias, Universidade de Sao Paulo, Rua do Matão 277, São Paulo 05508-900, Brazil
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1258
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Baumann S, Schoof S, Bolten M, Haering C, Takagi M, Shin-ya K, Arndt HD. Molecular Determinants of Microbial Resistance to Thiopeptide Antibiotics. J Am Chem Soc 2010; 132:6973-81. [DOI: 10.1021/ja909317n] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sascha Baumann
- Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany, and Biomedicinal Information Research Center (BIRC), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Sebastian Schoof
- Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany, and Biomedicinal Information Research Center (BIRC), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Marcel Bolten
- Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany, and Biomedicinal Information Research Center (BIRC), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Claudia Haering
- Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany, and Biomedicinal Information Research Center (BIRC), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Motoki Takagi
- Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany, and Biomedicinal Information Research Center (BIRC), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Kazuo Shin-ya
- Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany, and Biomedicinal Information Research Center (BIRC), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Hans-Dieter Arndt
- Fakultät Chemie, Technische Universität Dortmund, Otto-Hahn-Strasse 6, D-44221 Dortmund, Germany, Max-Planck-Institut für Molekulare Physiologie, Otto-Hahn-Strasse 11, D-44227 Dortmund, Germany, and Biomedicinal Information Research Center (BIRC), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
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1259
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Gluconeogenic carbon flow of tricarboxylic acid cycle intermediates is critical for Mycobacterium tuberculosis to establish and maintain infection. Proc Natl Acad Sci U S A 2010; 107:9819-24. [PMID: 20439709 DOI: 10.1073/pnas.1000715107] [Citation(s) in RCA: 263] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Metabolic adaptation to the host niche is a defining feature of the pathogenicity of Mycobacterium tuberculosis (Mtb). In vitro, Mtb is able to grow on a variety of carbon sources, but mounting evidence has implicated fatty acids as the major source of carbon and energy for Mtb during infection. When bacterial metabolism is primarily fueled by fatty acids, biosynthesis of sugars from intermediates of the tricarboxylic acid cycle is essential for growth. The role of gluconeogenesis in the pathogenesis of Mtb however remains unaddressed. Phosphoenolpyruvate carboxykinase (PEPCK) catalyzes the first committed step of gluconeogenesis. We applied genetic analyses and (13)C carbon tracing to confirm that PEPCK is essential for growth of Mtb on fatty acids and catalyzes carbon flow from tricarboxylic acid cycle-derived metabolites to gluconeogenic intermediates. We further show that PEPCK is required for growth of Mtb in isolated bone marrow-derived murine macrophages and in mice. Importantly, Mtb lacking PEPCK not only failed to replicate in mouse lungs but also failed to survive, and PEPCK depletion during the chronic phase of infection resulted in mycobacterial clearance. Mtb thus relies on gluconeogenesis throughout the infection. PEPCK depletion also attenuated Mtb in IFNgamma-deficient mice, suggesting that this enzyme represents an attractive target for chemotherapy.
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1260
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Comparison of in vitro activities of fluoroquinolone-like 2,4- and 1,3-diones. Antimicrob Agents Chemother 2010; 54:3011-4. [PMID: 20404126 DOI: 10.1128/aac.00190-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial resistance presents a difficult issue for fluoroquinolone treatment of bacterial infections. In previous work, we reported that 8-methoxy-quinazoline-2,4-diones are active against quinolone-resistant mutants of Escherichia coli. Here, we demonstrate the activity of a representative 8-methoxy-quinazoline-2,4-dione against quinolone-resistant gyrases. Furthermore, 8-methoxy-quinazoline-2,4-dione and other diones are shown to inhibit Staphylococcus aureus gyrase and topoisomerase IV with similar degrees of efficacy, suggesting that the diones might act as dual-targeting agents against S. aureus.
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1261
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Dosselli R, Gobbo M, Bolognini E, Campestrini S, Reddi E. Porphyrin-apidaecin conjugate as a new broad spectrum antibacterial agent. ACS Med Chem Lett 2010; 1:35-8. [PMID: 24900172 DOI: 10.1021/ml900021y] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 01/24/2010] [Indexed: 11/29/2022] Open
Abstract
The conjugation of the cationic antimicrobial peptide, apidaecin Ib, to the anionic photosensitizer, 5(4'-carboxyphenyl)-10,15,20-triphenylporphyrin (cTPP), afforded a new antibacterial agent effective, under light activation, against both Gram-positive and Gram-negative bacteria. At low concentrations (1.5-15 μM) the conjugate was able to reduce the survival of Escherichia coli cells by 3-4 log10, and most notably, it resulted photoactive also against hard-to-treat Pseudomonas aeruginosa, although at higher concentration (60 μM). Under similar conditions, the photosensitizer alone was only photoactive against Staphylococcus aureus while the unconjugated peptide was inactive against all the bacterial strains tested. This study shows the possibility of obtaining new broad-spectrum apidaecin-photosensitizer conjugates with potent antibacterial activity.
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Affiliation(s)
- Ryan Dosselli
- Department of Biology, University of Padova, via U. Bassi 58/B, 35131 Padova, Italy
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Marina Gobbo
- Department of Biology, University of Padova, via U. Bassi 58/B, 35131 Padova, Italy
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Erika Bolognini
- Department of Biology, University of Padova, via U. Bassi 58/B, 35131 Padova, Italy
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Sandro Campestrini
- Department of Biology, University of Padova, via U. Bassi 58/B, 35131 Padova, Italy
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Elena Reddi
- Department of Biology, University of Padova, via U. Bassi 58/B, 35131 Padova, Italy
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
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1262
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Abstract
Bacteria utilize multiple strategies to circumvent antibiotics, producing broad specificity exporters or enzymes that catalyze the modification of either antibiotics or their targets. A report in this issue of Structure provides the structural and catalytic mechanisms of LinB, an adenylyltransferase of E. faecium that confers resistance to the lincosamide antibiotic clindamycin.
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Affiliation(s)
- Jesse A Sundlov
- Department of Structural Biology, Hauptman-Woodward Medical Research Institute, State University of New York at Buffalo, Buffalo, NY, USA
| | - Andrew M Gulick
- Department of Structural Biology, Hauptman-Woodward Medical Research Institute, State University of New York at Buffalo, Buffalo, NY, USA.
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1263
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Antibiotic dose impact on resistance selection in the community: a mathematical model of beta-lactams and Streptococcus pneumoniae dynamics. Antimicrob Agents Chemother 2010; 54:2330-7. [PMID: 20231396 DOI: 10.1128/aac.00331-09] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae is a major pathogen in the community and presents high rates of resistance to the available antibiotics. To prevent antibiotic treatment failure caused by highly resistant bacteria, increasing the prescribed antibiotic dose has recently been suggested. The aim of the present study was to assess the influence of beta-lactam prescribed doses on the emergence of resistance and selection in the community. A mathematical model was constructed by combining S. pneumoniae pharmacodynamic and population-dynamic approaches. The received-dose heterogeneity in the population was specifically modeled. Simulations over a 50-year period were run to test the effects of dose distribution and antibiotic exposure frequency changes on community resistance patterns, as well as the accuracy of the defined daily dose as a predictor of resistance. When the frequency of antibiotic exposure per year was kept constant, dose levels had a strong impact on the levels of resistance after a 50-year simulation. The lowest doses resulted in a high prevalence of nonsusceptible strains (> or =70%) with MICs that were still low (1 mg/liter), whereas high doses resulted in a lower prevalence of nonsusceptible strains (<40%) and higher MICs (2 mg/liter). Furthermore, by keeping the volume of antibiotics constant in the population, different patterns of use (low antibiotic dose and high antibiotic exposure frequency versus high dose and low frequency) could lead to markedly different rates of resistance distribution and prevalence (from 10 to 100%). Our results suggest that pneumococcal resistance patterns in the community are strongly related to the individual beta-lactam doses received: limiting beta-lactam use while increasing the doses could help reduce the prevalence of resistance, although it should select for higher levels of resistance. Surveillance networks are therefore encouraged to collect both daily antibiotic exposure frequencies and individual prescribed doses.
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1264
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Rahman H, Austin B, Mitchell WJ, Morris PC, Jamieson DJ, Adams DR, Spragg AM, Schweizer M. Novel anti-infective compounds from marine bacteria. Mar Drugs 2010; 8:498-518. [PMID: 20411112 PMCID: PMC2857357 DOI: 10.3390/md8030498] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 11/16/2022] Open
Abstract
As a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, there have been demands for the development of new and effective antimicrobial compounds. Since the 1960s, the scientific literature has accumulated many publications about novel pharmaceutical compounds produced by a diverse range of marine bacteria. Indeed, marine micro-organisms continue to be a productive and successful focus for natural products research, with many newly isolated compounds possessing potentially valuable pharmacological activities. In this regard, the marine environment will undoubtedly prove to be an increasingly important source of novel antimicrobial metabolites, and selective or targeted approaches are already enabling the recovery of a significant number of antibiotic-producing micro-organisms. The aim of this review is to consider advances made in the discovery of new secondary metabolites derived from marine bacteria, and in particular those effective against the so called "superbugs", including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE), which are largely responsible for the increase in numbers of hospital acquired, i.e., nosocomial, infections.
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Affiliation(s)
- Hafizur Rahman
- School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK; E-Mails:
(H.R.);
(W.J.M.);
(P.C.M.);
(D.J.J.);
(M.S.)
| | - Brian Austin
- School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK; E-Mails:
(H.R.);
(W.J.M.);
(P.C.M.);
(D.J.J.);
(M.S.)
- Institute of Aquaculture, University of Stirling, Stirling, FK9 4LA, Scotland, UK
| | - Wilfrid J. Mitchell
- School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK; E-Mails:
(H.R.);
(W.J.M.);
(P.C.M.);
(D.J.J.);
(M.S.)
| | - Peter C. Morris
- School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK; E-Mails:
(H.R.);
(W.J.M.);
(P.C.M.);
(D.J.J.);
(M.S.)
| | - Derek J. Jamieson
- School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK; E-Mails:
(H.R.);
(W.J.M.);
(P.C.M.);
(D.J.J.);
(M.S.)
| | - David R. Adams
- Department of Chemistry, School of Engineering and Physical Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK; E-Mail:
(D.R.A.)
| | - Andrew Mearns Spragg
- Aquapharm Biodiscovery Limited, European Centre for Marine Biotechnology, Dunstaffnage Marine Laboratory, Oban, Argyll PA37 1QA, Scotland, UK; E-Mail:
(A.M.S.)
| | - Michael Schweizer
- School of Life Sciences, Heriot-Watt University, Riccarton, Edinburgh EH14 4AS, Scotland, UK; E-Mails:
(H.R.);
(W.J.M.);
(P.C.M.);
(D.J.J.);
(M.S.)
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1265
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Yang Z, Funabashi M, Nonaka K, Hosobuchi M, Shibata T, Pahari P, Van Lanen SG. Functional and kinetic analysis of the phosphotransferase CapP conferring selective self-resistance to capuramycin antibiotics. J Biol Chem 2010; 285:12899-905. [PMID: 20202936 DOI: 10.1074/jbc.m110.104141] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Capuramycin-related compounds, including A-500359s and A-503083s, are nucleoside antibiotics that inhibit the enzyme bacterial translocase I involved in peptidoglycan cell wall biosynthesis. Within the biosynthetic gene cluster for the A-500359s exists a gene encoding a putative aminoglycoside 3-phosphotransferase that was previously demonstrated to be highly expressed during the production of A-500359s and confers selective resistance to capuramycins when expressed in heterologous hosts. A similar gene (capP) was identified within the biosynthetic gene cluster for the A-503083s, and CapP is now shown to similarly confer selective resistance to capuramycins. Recombinant CapP was produced and purified from Escherichia coli, and the function of CapP is established as an ATP-dependent capuramycin phosphotransferase that regio-specifically transfers the gamma-phosphate to the 3''-hydroxyl of the unsaturated hexuronic acid moiety of A-503083 B. Kinetic analysis with the three major A-503083 congeners suggests that CapP preferentially phosphorylates A-503083s containing an aminocaprolactam moiety attached to the hexuronic acid, and bi-substrate kinetic analysis was consistent with CapP employing a sequential kinetic mechanism similar to most known aminoglycoside 3-phosphotransferases. The purified CapP product lost its antibiotic activity against Mycobacterium smegmatis, and this loss in bioactivity is primarily due to a 272-fold increase in the IC(50) in the bacterial translocase I-catalyzed reaction. The results establish CapP-mediated phosphorylation as a mechanism of resistance to capuramycins and now set the stage to explore this strategy of resistance as a potential mechanism inherent to pathogens and provide the impetus for preparing second generation analogues as a preemptive strike to such resistance strategies.
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Affiliation(s)
- Zhaoyong Yang
- College of Pharmacy, Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky 40536, USA
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1266
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Antistaphylococcal activities of telavancin tested alone and in combination by time-kill assay. Antimicrob Agents Chemother 2010; 54:2201-5. [PMID: 20160048 DOI: 10.1128/aac.01143-09] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Synergy time-kill studies against 40 methicillin-resistant Staphylococcus aureus (MRSA) strains of differing resistance phenotypes were conducted. Subinhibitory concentrations of telavancin were combined with sub-MIC concentrations of other antimicrobial agents that might be used in combination with telavancin to provide Gram-negative coverage. The highest incidence of synergy was found after 24 h with gentamicin (90% of strains), followed by ceftriaxone (88%), rifampin and meropenem (each 65%), cefepime (45%), and ciprofloxacin (38%) for combinations tested at or below the intermediate breakpoint for each agent.
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1267
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Bhunia A, Domadia PN, Torres J, Hallock KJ, Ramamoorthy A, Bhattacharjya S. NMR structure of pardaxin, a pore-forming antimicrobial peptide, in lipopolysaccharide micelles: mechanism of outer membrane permeabilization. J Biol Chem 2010; 285:3883-3895. [PMID: 19959835 PMCID: PMC2823531 DOI: 10.1074/jbc.m109.065672] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2009] [Revised: 11/02/2009] [Indexed: 11/06/2022] Open
Abstract
Lipopolysaccharide (LPS), the major constituent of the outer membrane of Gram-negative bacteria, is an important element against permeability of bactericidal agents, including antimicrobial peptides. However, structural determinants of antimicrobial peptides for LPS recognition are not clearly understood. Pardaxins (Pa1, Pa2, Pa3, and Pa4) are a group of pore-forming bactericidal peptides found in the mucous glands of sole fishes. Despite having a low net positive charge, pardaxins contain a broad spectrum of antibacterial activities. To elucidate the structural basis of LPS interactions of pardaxins, herein, we report the first three-dimensional structure of Pa4 bound to LPS micelles. The binding kinetics of Pa4 with LPS is estimated using [(15)N-Leu-19] relaxation dispersion NMR experiments. LPS/Pa4 interactions are further characterized by a number of biophysical methods, including isothermal titration calorimetry, (31)P NMR, saturation transfer difference NMR, dynamic light scattering, and IR spectroscopy. In the LPS-Pa4 complex, Pa4 adopts a unique helix-turn-helix conformation resembling a "horseshoe." Interestingly, the LPS-bound structure of Pa4 shows striking differences with the structures determined in lipid micelles or organic solvents. Saturation transfer difference NMR identifies residues of Pa4 that are intimately associated with LPS micelles. Collectively, our results provide mechanistic insights into the outer membrane permeabilization by pardaxin.
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Affiliation(s)
- Anirban Bhunia
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 and
| | - Prerna N Domadia
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 and
| | - Jaume Torres
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 and
| | - Kevin J Hallock
- the Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Ayyalusamy Ramamoorthy
- the Department of Chemistry and Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055.
| | - Surajit Bhattacharjya
- From the School of Biological Sciences, Division of Structural and Computational Biology, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 and.
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1268
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Salsi E, Bayden AS, Spyrakis F, Amadasi A, Campanini B, Bettati S, Dodatko T, Cozzini P, Kellogg GE, Cook PF, Roderick SL, Mozzarelli A. Design of O-acetylserine sulfhydrylase inhibitors by mimicking nature. J Med Chem 2010; 53:345-56. [PMID: 19928859 DOI: 10.1021/jm901325e] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The inhibition of cysteine biosynthesis in prokaryotes and protozoa has been proposed to be relevant for the development of antibiotics. Haemophilus influenzae O-acetylserine sulfhydrylase (OASS), catalyzing l-cysteine formation, is inhibited by the insertion of the C-terminal pentapeptide (MNLNI) of serine acetyltransferase into the active site. Four-hundred MNXXI pentapeptides were generated in silico, docked into OASS active site using GOLD, and scored with HINT. The terminal P5 Ile accounts for about 50% of the binding energy. Glu or Asp at position P4 and, to a lesser extent, at position P3 also significantly contribute to the binding interaction. The predicted affinity of 14 selected pentapeptides correlated well with the experimentally determined dissociation constants. The X-ray structure of three high affinity pentapeptide-OASS complexes were compared with the docked poses. These results, combined with a GRID analysis of the active site, allowed us to define a pharmacophoric scaffold for the design of peptidomimetic inhibitors.
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Affiliation(s)
- Enea Salsi
- Department of Biochemistry and Molecular Biology, University of Parma, Italy.
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1269
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Gobbo M, Poloni C, De Zotti M, Peggion C, Biondi B, Ballano G, Formaggio F, Toniolo C. Synthesis, Preferred Conformation, and Membrane Activity of Medium-Length Peptaibiotics: Tylopeptin B. Chem Biol Drug Des 2010; 75:169-81. [DOI: 10.1111/j.1747-0285.2009.00920.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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1270
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Hong Q, Minter DE, Franzblau SG, Arfan M, Amin H, Reinecke MG. Anti-tuberculosis Compounds from Mallotus philippinensis. Nat Prod Commun 2010. [DOI: 10.1177/1934578x1000500208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Bioassay-directed fractionation of the organic extract of Mallotus philippinensis gave five compounds (1-5), the most active of which against Mycobacterium tuberculosis was a new compound, 8-cinnamoyl-5,7-dihydroxy-2,2-dimethyl-6-geranylchromene (1) for which the name mallotophilippen F is suggested. Compound (2), 8-cinnamoyl-2,2-dimethyl-7-hydroxy-5-methoxychromene, was isolated from a natural source for the first time, while the remaining three compounds, rottlerin (3), isoallorottlerin=isorottlerin (4) and the so-called “red compound,” 8-cinnamoyl-5,7-dihydroxy-2,2,6-trimethylchromene (5), had been isolated previously from this plant. All compounds were identified by analysis of their spectra including 2D-NMR, which was used to correct the literature NMR spectral assignments of compounds 2-4. The C-13 NMR of 5 is reported for the first time.
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Affiliation(s)
- Qi Hong
- Department of Chemistry, Texas Christian University, Fort Worth, TX 76129, USA
| | - David E. Minter
- Department of Chemistry, Texas Christian University, Fort Worth, TX 76129, USA
| | - Scott G. Franzblau
- Institute for Tuberculosis Research University of Illinois, Chicago, IL 60612-7231, USA
| | - Mohammad Arfan
- Institute of Chemical Sciences, University of Peshawar, Peshawar 25120, Pakistan
| | - Hazrat Amin
- Institute of Chemical Sciences, University of Peshawar, Peshawar 25120, Pakistan
| | - Manfred G. Reinecke
- Department of Chemistry, Texas Christian University, Fort Worth, TX 76129, USA
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1271
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Abstract
The emergence of drug-resistant pathogens has prompted the search for new antibacterials. In this issue of Chemistry & Biology, Starosta et al. identify specific thiopeptide-antibiotic precursor lead compounds using three complementary high-throughput translation machinery assays.
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Affiliation(s)
- Anna-Skrollan Geiermann
- Institute of Organic Chemistry, Center for Molecular Biosciences (CMBI), University of Innsbruck, 6020 Innsbruck, Austria
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1272
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Antibiotic sensitivity profiles determined with an Escherichia coli gene knockout collection: generating an antibiotic bar code. Antimicrob Agents Chemother 2010; 54:1393-403. [PMID: 20065048 DOI: 10.1128/aac.00906-09] [Citation(s) in RCA: 230] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
We have defined a sensitivity profile for 22 antibiotics by extending previous work testing the entire KEIO collection of close to 4,000 single-gene knockouts in Escherichia coli for increased susceptibility to 1 of 14 different antibiotics (ciprofloxacin, rifampin [rifampicin], vancomycin, ampicillin, sulfamethoxazole, gentamicin, metronidazole, streptomycin, fusidic acid, tetracycline, chloramphenicol, nitrofurantoin, erythromycin, and triclosan). We screened one or more subinhibitory concentrations of each antibiotic, generating more than 80,000 data points and allowing a reduction of the entire collection to a set of 283 strains that display significantly increased sensitivity to at least one of the antibiotics. We used this reduced set of strains to determine a profile for eight additional antibiotics (spectinomycin, cephradine, aztreonem, colistin, neomycin, enoxacin, tobramycin, and cefoxitin). The profiles for the 22 antibiotics represent a growing catalog of sensitivity fingerprints that can be separated into two components, multidrug-resistant mutants and those mutants that confer relatively specific sensitivity to the antibiotic or type of antibiotic tested. The latter group can be represented by a set of 20 to 60 strains that can be used for the rapid typing of antibiotics by generating a virtual bar code readout of the specific sensitivities. Taken together, these data reveal the complexity of intrinsic resistance and provide additional targets for the design of codrugs (or combinations of drugs) that potentiate existing antibiotics.
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1273
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Blueprint for antimicrobial hit discovery targeting metabolic networks. Proc Natl Acad Sci U S A 2010; 107:1082-7. [PMID: 20080587 DOI: 10.1073/pnas.0909181107] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Advances in genome analysis, network biology, and computational chemistry have the potential to revolutionize drug discovery by combining system-level identification of drug targets with the atomistic modeling of small molecules capable of modulating their activity. To demonstrate the effectiveness of such a discovery pipeline, we deduced common antibiotic targets in Escherichia coli and Staphylococcus aureus by identifying shared tissue-specific or uniformly essential metabolic reactions in their metabolic networks. We then predicted through virtual screening dozens of potential inhibitors for several enzymes of these reactions and showed experimentally that a subset of these inhibited both enzyme activities in vitro and bacterial cell viability. This blueprint is applicable for any sequenced organism with high-quality metabolic reconstruction and suggests a general strategy for strain-specific antiinfective therapy.
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1274
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Szabo RM. Perioperative antibiotics for carpal tunnel surgery. J Hand Surg Am 2010; 35:122-4. [PMID: 20117313 DOI: 10.1016/j.jhsa.2009.10.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Accepted: 10/22/2009] [Indexed: 02/02/2023]
Affiliation(s)
- Robert M Szabo
- Department of Orthopaedic Surgery, University of California, Davis, Sacramento, CA, USA.
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1275
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Funabashi M, Baba S, Nonaka K, Hosobuchi M, Fujita Y, Shibata T, Van Lanen SG. The Biosynthesis of Liposidomycin-like A-90289 Antibiotics Featuring a New Type of Sulfotransferase. Chembiochem 2009; 11:184-90. [DOI: 10.1002/cbic.200900665] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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1276
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Yang B, Zöllner T, Gebhardt P, Möllmann U, Miller MJ. Preparation and biological evaluation of novel leucomycin analogs derived from nitroso Diels-Alder reactions. Org Biomol Chem 2009; 8:691-7. [PMID: 20090988 DOI: 10.1039/b922450e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of 10,13-disubstituted 16-membered macrolides was synthesized using nitroso Diels-Alder reactions of leucomycin A7. Despite the extensive constituent functionalities in leucomycin, the hetero cycloaddition reactions proceeded in a highly regio- and stereoselective fashion. Subsequent chemical modifications of the nitroso cycloadducts, including N-O bond reduction, were also conducted. Most leucomycin derivatives retained antibiotic profiles similar to leucomycin A7, and, in contrast to leucomycin itself, several exhibited moderate antiproliferative and cytotoxic activity.
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Affiliation(s)
- Baiyuan Yang
- Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland ScienceHall, Notre Dame, Indiana 46556, USA
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1277
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Gross PJ, Hartmann CE, Nieger M, Bräse S. Synthesis of Methoxyfumimycin with 1,2-Addition to Ketimines. J Org Chem 2009; 75:229-32. [DOI: 10.1021/jo902026s] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Patrick J. Gross
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Caroline E. Hartmann
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
| | - Martin Nieger
- Laboratory of Inorganic Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Stefan Bräse
- Institute of Organic Chemistry, Karlsruhe Institute of Technology, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany
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