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Yan S, Zeng M, Wang H, Zhang H. Micromonospora: A Prolific Source of Bioactive Secondary Metabolites with Therapeutic Potential. J Med Chem 2022; 65:8735-8771. [PMID: 35766919 DOI: 10.1021/acs.jmedchem.2c00626] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Micromonospora, one of the most important actinomycetes genera, is well-known as the treasure trove of bioactive secondary metabolites (SMs). Herein, together with an in-depth genomic analysis of the reported Micromonospora strains, all SMs from this genus are comprehensively summarized, containing structural features, bioactive properties, and mode of actions as well as their biosynthetic and chemical synthesis pathways. The perspective enables a detailed view of Micromonospora-derived SMs, which will enrich the chemical diversity of natural products and inspire new drug discovery in the pharmaceutical industry.
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Affiliation(s)
- Suqi Yan
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
| | - Mingyuan Zeng
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
| | - Hong Wang
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
| | - Huawei Zhang
- School of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
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2
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Rodríguez D, Maneiro M, Vázquez-Ucha JC, Beceiro A, González-Bello C. 6-Arylmethylidene Penicillin-Based Sulfone Inhibitors for Repurposing Antibiotic Efficiency in Priority Pathogens. J Med Chem 2020; 63:3737-3755. [PMID: 32196336 DOI: 10.1021/acs.jmedchem.0c00127] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The ability of 6-(aryl)methylidene penicillin-based sulfones 1-7 to repurpose β-lactam antibiotics activity with bacterial species that carry carbapenem-hydrolyzing class D β-lactamases (OXA-23, OXA-24/40 and OXA-48), as well as with class A (TEM-1, CTX-M-2) and class C (CMY-2, DHA-1) enzymes, is reported. The combinations imipenem/3 and imipenem/4 restored almost completely the antibiotic efficacy in OXA-23 and OXA-24/40 carbapenemase-producing A. baumannii strains (1 μg mL-1) and also provided good results for OXA-48 carbapenemase-producing K. pneumoniae strains (4 μg mL-1). Compounds 2-6 in combinations with ceftazidime and ampicillin were also efficient in restoring antibiotic efficacy in E. coli strains carrying class C (CMY-2 and DHA-1) and class A (TEM-1 and CTX-M-2) β-lactamase enzymes, respectively. Kinetic and inhibition studies with the OXA-24/40 enzyme, protein mass spectrometry analysis and docking studies allowed us to gain an insight into the inhibition mechanism and the experimentally observed differences between the ligands.
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Affiliation(s)
- Diana Rodríguez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain
| | - María Maneiro
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain
| | - Juan C Vázquez-Ucha
- Servicio de Microbiología do Complexo Hospitalario Universitario da Coruña (CHUAC), Instituto de Investigación Biomédica da Coruña (INIBIC), Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Alejandro Beceiro
- Servicio de Microbiología do Complexo Hospitalario Universitario da Coruña (CHUAC), Instituto de Investigación Biomédica da Coruña (INIBIC), Xubias de Arriba, 84, 15006 A Coruña, Spain
| | - Concepción González-Bello
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS), Departamento de Química Orgánica, Universidade de Santiago de Compostela, Jenaro de la Fuente s/n, 15782 Santiago de Compostela, Spain
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3
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Kinetic characterization and molecular docking of novel allosteric inhibitors of aminoglycoside phosphotransferases. Biochim Biophys Acta Gen Subj 2017; 1861:3464-3473. [DOI: 10.1016/j.bbagen.2016.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/07/2016] [Accepted: 09/11/2016] [Indexed: 11/21/2022]
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4
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Valiullina ZR, Selezneva NK, Khursan SL, Gimalova FA, Miftakhov MS. Functionalized β-lactams based on (E)-1-(furan-2-yl)-N-[(4-methoxyphenyl)methyl]methanimine and its imine–imine rearrangement initiated by potassium hydride. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2016. [DOI: 10.1134/s1070428016070058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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References. Antibiotics (Basel) 2015. [DOI: 10.1128/9781555819316.refs] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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6
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Hsieh YC, Chen MC, Hsu CC, Chan SI, Yang YS, Chen CJ. Crystal structures of vertebrate dihydropyrimidinase and complexes from Tetraodon nigroviridis with lysine carbamylation: metal and structural requirements for post-translational modification and function. J Biol Chem 2013; 288:30645-30658. [PMID: 24005677 DOI: 10.1074/jbc.m113.496778] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lysine carbamylation, a post-translational modification, facilitates metal coordination for specific enzymatic activities. We have determined structures of the vertebrate dihydropyrimidinase from Tetraodon nigroviridis (TnDhp) in various states: the apoenzyme as well as two forms of the holoenzyme with one and two metals at the catalytic site. The essential active-site structural requirements have been identified for the possible existence of four metal-mediated stages of lysine carbamylation. Only one metal is sufficient for stabilizing lysine carbamylation; however, the post-translational lysine carbamylation facilitates additional metal coordination for the regulation of specific enzymatic activities through controlling the conformations of two dynamic loops, Ala(69)-Arg(74) and Met(158)-Met(165), located in the tunnel for the substrate entrance. The substrate/product tunnel is in the "open form" in the apo-TnDhp, in the "intermediate state" in the monometal TnDhp, and in the "closed form" in the dimetal TnDhp structure, respectively. Structural comparison also suggests that the C-terminal tail plays a role in the enzymatic function through interactions with the Ala(69)-Arg(74) dynamic loop. In addition, the structures of the dimetal TnDhp in complexes with hydantoin, N-carbamyl-β-alanine, and N-carbamyl-β-amino isobutyrate as well as apo-TnDhp in complex with a product analog, N-(2-acetamido)-iminodiacetic acid, have been determined. These structural results illustrate how a protein exploits unique lysines and the metal distribution to accomplish lysine carbamylation as well as subsequent enzymatic functions.
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Affiliation(s)
- Yin-Cheng Hsieh
- From the Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - Mei-Chun Chen
- the Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Ching-Chen Hsu
- the Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30010, Taiwan
| | - Sunney I Chan
- the Institute of Chemistry, Academia Sinica, Taipei 11529, Taiwan,; the Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 911525
| | - Yuh-Shyong Yang
- the Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30010, Taiwan,.
| | - Chun-Jung Chen
- From the Life Science Group, Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan,; the Department of Physics, National Tsing Hua University, Hsinchu 30043, Taiwan, and; the Institute of Biotechnology and; University Center for Bioscience and Biotechnology, National Cheng Kung University, 1 University Road, Tainan City 701, Taiwan.
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7
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Bhattacharya R, Kundu B, Nandi SK, Basu D. Systematic approach to treat chronic osteomyelitis through localized drug delivery system: bench to bed side. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2013; 33:3986-93. [PMID: 23910305 DOI: 10.1016/j.msec.2013.05.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Revised: 03/20/2013] [Accepted: 05/16/2013] [Indexed: 01/12/2023]
Abstract
Chronic osteomyelitis is a challenging setback to the orthopedic surgeons in deciding an optimal therapeutic strategy. Conversely, patients feel frustrated of the therapeutic outcomes and development of adverse drug effects, if any. Present investigation deals with extensive approach incorporating in vivo animal experimentation and human application to treat chronic osteomyelitis, using antibiotic loaded porous hydroxyapatite scaffolds. Micro- to macro-porous hydroxyapatite scaffolds impregnated with antibiotic ceftriaxone-sulbactam sodium (CFS) were fabricated and subsequently evaluated by in vivo animal model after developing osteomyelitis in rabbit tibia. Finally 10 nos. of human osteomyelitis patients involving long bone and mandible were studied for histopathology, radiology, pus culture, 3D CT etc. up to 8-18 months post-operatively. It was established up to animal trial stage that 50N50H samples [with 50-55% porosity, average pore size 110 μm, higher interconnectivity (10-100 μm), and moderately high drug adsorption efficiency (50%)] showed efficient drug release up to 42 days than parenteral group based on infection eradication and new bone formation. In vivo human bone showed gradual evidence of new bone formation and fracture union with organized callus without recurrence of infection even after 8 months. This may be a new, alternative, cost effective and ideal therapeutic strategy for chronic osteomyelitis treatment in human patients.
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Affiliation(s)
- Rupnarayan Bhattacharya
- Department of Plastic Surgery, R. G. Kar Medical College and Hospital (RGKMCH), Kolkata 700004, India
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8
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Smith CA, Frase H, Toth M, Kumarasiri M, Wiafe K, Munoz J, Mobashery S, Vakulenko SB. Structural basis for progression toward the carbapenemase activity in the GES family of β-lactamases. J Am Chem Soc 2012; 134:19512-5. [PMID: 23148776 PMCID: PMC3610538 DOI: 10.1021/ja308197j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Carbapenem antibiotics have become therapeutics of last resort for the treatment of difficult infections. The emergence of class-A β-lactamases that have the ability to inactivate carbapenems in the past few years is a disconcerting clinical development in light of the diminished options for treatment of infections. A member of the GES-type β-lactamase family, GES-1, turns over imipenem poorly, but the GES-5 β-lactamase is an avid catalyst for turnover of this antibiotic. We report herein high-resolution X-ray structures of the apo GES-5 β-lactamase and the GES-1 and GES-5 β-lactamases in complex with imipenem. The latter are the first structures of native class-A carbapenemases with a clinically used carbapenem antibiotic in the active site. The structural information is supplemented by information from molecular dynamics simulations, which collectively for the first time discloses how the second step of catalysis by these enzymes, namely, hydrolytic deacylation of the acyl-enzyme species, takes place effectively in the case of the GES-5 β-lactamase and significantly less so in GES-1. This information illuminates one evolutionary path that nature has taken in the direction of the inexorable emergence of resistance to carbapenem antibiotics.
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Affiliation(s)
- Clyde A. Smith
- Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Hilary Frase
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Marta Toth
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Malika Kumarasiri
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Kwame Wiafe
- Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Jared Munoz
- Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California 94025, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Sergei B. Vakulenko
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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Characterization and quantitation of a novel β-lactamase gene found in a wastewater treatment facility and the surrounding coastal ecosystem. Appl Environ Microbiol 2011; 77:8226-33. [PMID: 21965412 DOI: 10.1128/aem.02732-10] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Wastewater treatment plants (WWTPs) are engineered structures that collect, concentrate, and treat human waste, ultimately releasing treated wastewater into local environments. While WWTPs efficiently remove most biosolids, it has been shown that many antibiotics and antibiotic-resistant bacteria can survive the treatment process. To determine how WWTPs influence the concentration and dissemination of antibiotic-resistant genes into the environment, a functional metagenomic approach was used to identify a novel antibiotic resistance gene within a WWTP, and quantitative PCR (qPCR) was used to determine gene copy numbers within the facility and the local coastal ecosystem. From the WWTP metagenomic library, the fosmid insert contained in one highly resistant clone (MIC, ≈ 416 μg ml(-1) ampicillin) was sequenced and annotated, revealing 33 putative genes, including a 927-bp gene that is 42% identical to a functionally characterized β-lactamase from Staphylococcus aureus PC1. Isolation and subcloning of this gene, referred to as bla(M-1), conferred ampicillin resistance to its Escherichia coli host. When normalized to volume, qPCR showed increased concentrations of bla(M-1) during initial treatment stages but 2-fold-decreased concentrations during the final treatment stage. The concentration ng(-1) DNA increased throughout the WWTP process from influent to effluent, suggesting that bla(M-1) makes up a significant proportion of the overall genetic material being released into the coastal ecosystem. Average discharge was estimated to be 3.9 × 10(14) copies of the bla(M-1) gene released daily into this coastal ecosystem. Furthermore, the gene was observed in all sampled coastal water and sediment samples surrounding the facility. Our results suggest that WWTPs may be a pathway for the dissemination of novel antibiotic resistance genes into the environment.
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10
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Docquier JD, Benvenuti M, Calderone V, Rossolini GM, Mangani S. Structure of the extended-spectrum β-lactamase TEM-72 inhibited by citrate. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:303-6. [PMID: 21393831 PMCID: PMC3053151 DOI: 10.1107/s1744309110054680] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Accepted: 12/29/2010] [Indexed: 11/10/2022]
Abstract
TEM-72, a class A β-lactamase identified in isolates of Enterobacteriaceae, is a quadruple mutant of TEM-1 (Q39K, M182T, G238S and E240K) and shows extended-spectrum β-lactamase (ESBL) properties arising from the G238S and E240K substitutions. Although many structures of TEM variants have been published, they do not include an enzyme with the simultaneous presence of both of the ESBL-conferring G238S and E240K substitutions. Furthermore, the structure shows the presence of a citrate anion bound to the TEM-72 active site, where it interacts with all of the conserved residues of class A β-lactamases. The present structure supports the use of polycarboxylates as a scaffold for the design of broad-spectrum inhibitors of serine β-lactamases.
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Affiliation(s)
- Jean-Denis Docquier
- Dipartimento di Biologia Molecolare, Laboratorio di Fisiologia e Biotecnologia dei Microrganismi, Università di Siena, I-53100 Siena, Italy
| | | | - Vito Calderone
- Magnetic Resonance Center CERM, Università di Firenze, I-50019 Sesto Fiorentino, Italy
| | - Gian-Maria Rossolini
- Dipartimento di Biologia Molecolare, Laboratorio di Fisiologia e Biotecnologia dei Microrganismi, Università di Siena, I-53100 Siena, Italy
- U. O. C. Microbiologia e Virologia, Università di Siena, I-53100 Siena, Italy
| | - Stefano Mangani
- Dipartimento di Chimica, Università di Siena, I-53100 Siena, Italy
- Magnetic Resonance Center CERM, Università di Firenze, I-50019 Sesto Fiorentino, Italy
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11
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Bou G, Santillana E, Sheri A, Beceiro A, Sampson J, Kalp M, Bethel CR, Distler AM, Drawz SM, Pagadala SRR, van den Akker F, Bonomo RA, Romero A, Buynak JD. Design, synthesis, and crystal structures of 6-alkylidene-2'-substituted penicillanic acid sulfones as potent inhibitors of Acinetobacter baumannii OXA-24 carbapenemase. J Am Chem Soc 2010; 132:13320-31. [PMID: 20822105 PMCID: PMC3393087 DOI: 10.1021/ja104092z] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Class D β-lactamases represent a growing and diverse class of penicillin-inactivating enzymes that are usually resistant to commercial β-lactamase inhibitors. As many such enzymes are found in multi-drug resistant (MDR) Acinetobacter baumannii and Pseudomonas aeruginosa, novel β-lactamase inhibitors are urgently needed. Five unique 6-alkylidene-2'-substituted penicillanic acid sulfones (1-5) were synthesized and tested against OXA-24, a clinically important β-lactamase that inactivates carbapenems and is found in A. baumannii. Based upon the roles Tyr112 and Met223 play in the OXA-24 β-lactamase, we also engineered two variants (Tyr112Ala and Tyr112Ala,Met223Ala) to test the hypothesis that the hydrophobic tunnel formed by these residues influences inhibitor recognition. IC(50) values against OXA-24 and two OXA-24 β-lactamase variants ranged from 10 ± 1 (4 vs WT) to 338 ± 20 nM (5 vs Tyr112Ala, Met223Ala). Compound 4 possessed the lowest K(i) (500 ± 80 nM vs WT), and 1 possessed the highest inactivation efficiency (k(inact)/K(i) = 0.21 ± 0.02 μM(-1) s(-1)). Electrospray ionization mass spectrometry revealed a single covalent adduct, suggesting the formation of an acyl-enzyme intermediate. X-ray structures of OXA-24 complexed to four inhibitors (2.0-2.6 Å) reveal the formation of stable bicyclic aromatic intermediates with their carbonyl oxygen in the oxyanion hole. These data provide the first structural evidence that 6-alkylidene-2'-substituted penicillin sulfones are effective mechanism-based inactivators of class D β-lactamases. Their unique chemistry makes them developmental candidates. Mechanisms for class D hydrolysis and inhibition are discussed, and a pathway for the evolution of the BlaR1 sensor of Staphylococcus aureus to the class D β-lactamases is proposed.
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Affiliation(s)
| | | | | | | | - Jared Sampson
- Departments of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Matthew Kalp
- Departments of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH
| | | | - Anne M. Distler
- Department of Pharmacology, Case Western Reserve University School of Medicine
| | - Sarah M. Drawz
- Department of Pathology, Case Western Reserve University School of Medicine
| | | | - Focco van den Akker
- Departments of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Robert A. Bonomo
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, OH
- Department of Pharmacology, Case Western Reserve University School of Medicine
- Department of Molecular Biology and Microbiology, Case Western Reserve University
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12
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Kundu B, Soundrapandian C, Nandi SK, Mukherjee P, Dandapat N, Roy S, Datta BK, Mandal TK, Basu D, Bhattacharya RN. Development of New Localized Drug Delivery System Based on Ceftriaxone-Sulbactam Composite Drug Impregnated Porous Hydroxyapatite: A Systematic Approach for In Vitro and In Vivo Animal Trial. Pharm Res 2010; 27:1659-76. [DOI: 10.1007/s11095-010-0166-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 04/22/2010] [Indexed: 10/19/2022]
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Affiliation(s)
- Bimal K. Banik
- Dept. Chemistry, University of Texas-Pan American, W. University Drive 1201, Edinburg, 78539 USA
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14
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Toth M, Smith C, Frase H, Mobashery S, Vakulenko S. An antibiotic-resistance enzyme from a deep-sea bacterium. J Am Chem Soc 2010; 132:816-23. [PMID: 20000704 PMCID: PMC2826318 DOI: 10.1021/ja908850p] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe herein a highly proficient class A beta-lactamase OIH-1 from the bacterium Oceanobacillus iheyensis, whose habitat is the sediment at a depth of 1050 m in the Pacific Ocean. The OIH-1 structure was solved by molecular replacement and refined at 1.25 A resolution. OIH-1 has evolved to be an extremely halotolerant beta-lactamase capable of hydrolyzing its substrates in the presence of NaCl at saturating concentration. Not only is this the most highly halotolerant bacterial enzyme structure known to date, it is also the highest resolution halophilic protein structure yet determined. Evolution of OIH-1 in the salinity of the ocean has resulted in a molecular surface that is coated with acidic residues, a marked difference from beta-lactamases of terrestrial sources. OIH-1 is the first example of an antibiotic-resistance enzyme that has evolved in the depths of the ocean in isolation from clinical selection and gives us an extraordinary glimpse into protein evolution under extreme conditions. It represents evidence for the existence of a reservoir of antibiotic-resistance enzymes in nature among microbial populations from deep oceanic sources.
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Affiliation(s)
- Marta Toth
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Clyde Smith
- Stanford Synchrotron Radiation Lightsource, Stanford University, Menlo Park, CA 94025
| | - Hilary Frase
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Sergei Vakulenko
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
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De Wals PY, Doucet N, Pelletier JN. High tolerance to simultaneous active-site mutations in TEM-1 beta-lactamase: Distinct mutational paths provide more generalized beta-lactam recognition. Protein Sci 2009; 18:147-60. [PMID: 19177359 DOI: 10.1002/pro.25] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The diversity in substrate recognition spectra exhibited by various beta-lactamases can result from one or a few mutations in the active-site area. Using Escherichia coli TEM-1 beta-lactamase as a template that efficiently hydrolyses penicillins, we performed site-saturation mutagenesis simultaneously on two opposite faces of the active-site cavity. Residues 104 and 105 as well as 238, 240, and 244 were targeted to verify their combinatorial effects on substrate specificity and enzyme activity and to probe for cooperativity between these residues. Selection for hydrolysis of an extended-spectrum cephalosporin, cefotaxime (CTX), led to the identification of a variety of novel mutational combinations. In vivo survival assays and in vitro characterization demonstrated a general tendency toward increased CTX and decreased penicillin resistance. Although selection was undertaken with CTX, productive binding (K(M)) was improved for all substrates tested, including benzylpenicillin for which catalytic turnover (k(cat)) was reduced. This indicates broadened substrate specificity, resulting in more generalized (or less specialized) variants. In most variants, the G238S mutation largely accounted for the observed properties, with additional mutations acting in an additive fashion to enhance these properties. However, the most efficient variant did not harbor the mutation G238S but combined two neighboring mutations that acted synergistically, also providing a catalytic generalization. Our exploration of concurrent mutations illustrates the high tolerance of the TEM-1 active site to multiple simultaneous mutations and reveals two distinct mutational paths to substrate spectrum diversification.
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Affiliation(s)
- Pierre-Yves De Wals
- Département de Biochimie, Université de Montréal, Montréal Québec, Canada H3C 3J7
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Hugonnet JE, Tremblay LW, Boshoff HI, Barry CE, Blanchard JS. Meropenem-clavulanate is effective against extensively drug-resistant Mycobacterium tuberculosis. Science 2009; 323:1215-8. [PMID: 19251630 PMCID: PMC2679150 DOI: 10.1126/science.1167498] [Citation(s) in RCA: 372] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
beta-lactam antibiotics are ineffective against Mycobacterium tuberculosis, being rapidly hydrolyzed by the chromosomally encoded blaC gene product. The carbapenem class of beta-lactams are very poor substrates for BlaC, allowing us to determine the three-dimensional structure of the covalent BlaC-meropenem covalent complex at 1.8 angstrom resolution. When meropenem was combined with the beta-lactamase inhibitor clavulanate, potent activity against laboratory strains of M. tuberculosis was observed [minimum inhibitory concentration (MIC(meropenem)) less than 1 microgram per milliliter], and sterilization of aerobically grown cultures was observed within 14 days. In addition, this combination exhibited inhibitory activity against anaerobically grown cultures that mimic the "persistent" state and inhibited the growth of 13 extensively drug-resistant strains of M. tuberculosis at the same levels seen for drug-susceptible strains. Meropenem and clavulanate are Food and Drug Administration-approved drugs and could potentially be used to treat patients with currently untreatable disease.
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Affiliation(s)
- Jean-Emmanuel Hugonnet
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Lee W. Tremblay
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Helena I. Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Clifton E. Barry
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - John S. Blanchard
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Nukaga M, Bethel CR, Thomson JM, Hujer AM, Distler A, Anderson VE, Knox JR, Bonomo RA. Inhibition of class A beta-lactamases by carbapenems: crystallographic observation of two conformations of meropenem in SHV-1. J Am Chem Soc 2008; 130:12656-62. [PMID: 18761444 DOI: 10.1021/ja7111146] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Carbapenem antibiotics are often the "last resort" in the treatment of infections caused by bacteria resistant to penicillins and cephalosporins. To understand why meropenem is resistant to hydrolysis by the SHV-1 class A beta-lactamase, the atomic structure of meropenem inactivated SHV-1 was solved to 1.05 A resolution. Two conformations of the Ser70 acylated intermediate are observed in the SHV-1-meropenem complex; the meropenem carbonyl oxygen atom of the acyl-enzyme is in the oxyanion hole in one conformation, while in the other conformation it is not. Although the structures of the SHV-1 apoenzyme and the SHV-1-meropenem complex are very similar (0.29 A rmsd for Calpha atoms), the orientation of the conserved Ser130 is different. Notably, the Ser130-OH group of the SHV-1-meropenem complex is directed toward Lys234Nz, while the Ser130-OH of the apo enzyme is oriented toward the Lys73 amino group. This altered position may affect proton transfer via Ser130 and the rate of hydrolysis. A most intriguing finding is the crystallographic detection of protonation of the Glu166 known to be involved in the deacylation mechanism. The critical deacylation water molecule has an additional hydrogen-bonding interaction with the OH group of meropenem's 6alpha-1 R-hydroxyethyl substituent. This interaction may weaken the nucleophilicity and/or change the direction of the lone pair of electrons of the water molecule and result in poor turnover of meropenem by the SHV-1 beta-lactamase. Using timed mass spectrometry, we further show that meropenem is covalently attached to SHV-1 beta-lactamase for at least 60 min. These observations explain key properties of meropenem's ability to resist hydrolysis by SHV-1 and lead to important insights regarding future carbapenem and beta-lactamase inhibitor design.
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Affiliation(s)
- Michiyosi Nukaga
- Faculty of Pharmaceutical Sciences, Josai International University, Togane City, Chiba 283-8555, Japan
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18
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Johnson JW, Evanoff DP, Savard ME, Lange G, Ramadhar TR, Assoud A, Taylor NJ, Dmitrienko GI. Cyclobutanone Mimics of Penicillins: Effects of Substitution on Conformation and Hemiketal Stability. J Org Chem 2008; 73:6970-82. [PMID: 18710291 DOI: 10.1021/jo801274m] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jarrod W. Johnson
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Darryl P. Evanoff
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Marc E. Savard
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Gerald Lange
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Timothy R. Ramadhar
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Abdeljalil Assoud
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Nicholas J. Taylor
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Gary I. Dmitrienko
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
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19
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Biochemical detection of a metallo-β-lactamase in carbapenem resistant strain ofStreptomyces sp. CN229 isolated from soil. ANN MICROBIOL 2007. [DOI: 10.1007/bf03175348] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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20
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Marrero A, Mallorquí-Fernández G, Guevara T, García-Castellanos R, Gomis-Rüth FX. Unbound and acylated structures of the MecR1 extracellular antibiotic-sensor domain provide insights into the signal-transduction system that triggers methicillin resistance. J Mol Biol 2006; 361:506-21. [PMID: 16846613 DOI: 10.1016/j.jmb.2006.06.046] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 06/15/2006] [Accepted: 06/16/2006] [Indexed: 11/25/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains are responsible for most hospital-onset bacterial infections. Lately, they have become a major threat to the community through infections of skin, soft tissue and respiratory tract, and subsequent septicaemia or septic shock. MRSA strains are resistant to most beta-lactam antibiotics (BLAs) as a result of the biosynthesis of a penicillin-binding protein with low affinity for BLAs, called PBP2a, PBP2' or MecA. This response is regulated by the chromosomal mec-divergon, which encodes a signal-transduction system including a transcriptional repressor, MecI, and a sensor/transducer, MecR1, as well as the structural mecA gene. This system is similar to those encoded by bla divergons in S. aureus and Bacillus licheniformis. MecR1 comprises an integral-membrane latent metalloprotease domain facing the cytosol and an extracellular sensor domain. The latter binds BLAs and transmits a signal through the membrane that eventually triggers activation of the metalloprotease moiety, which in turn switches off MecI-induced repression of mecA transcription. The MecR1 sensor domain, MecR1-PBD, reveals a two-domain structure of alpha/beta-type fold reminiscent of penicillin-binding proteins and beta-lactamases, and a catalytic serine residue as the ultimate cause for BLA-binding. Covalent complexes with benzylpenicillin and oxacillin provide evidence that serine acylation does not entail significant structural changes, thus supporting the hypothesis that additional extracellular segments of MecR1 are involved in signal transmission. The chemical nature of the residues shaping the active-site cleft favours stabilisation of the acyl enzyme complexes in MecR1-PBD, in contrast to the closely related OXA beta-lactamases, where the cleft is more likely to promote subsequent hydrolysis. The present structural data provide insights into the mec-encoded BLA-response mechanism and an explanation for kinetic differences in signal transmission with the related bla-encoded systems.
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Affiliation(s)
- Aniebrys Marrero
- Institut de Biologia Molecular de Barcelona, C.I.D.-C.S.I.C. C/Jordi Girona, 18-26 08034 Barcelona, Spain
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21
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Phillips OA. β-Lactamase inhibitors: a survey of the patent literature 2000 – 2004. Expert Opin Ther Pat 2006. [DOI: 10.1517/13543776.16.3.319] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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22
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Buynak JD. Understanding the longevity of the beta-lactam antibiotics and of antibiotic/beta-lactamase inhibitor combinations. Biochem Pharmacol 2005; 71:930-40. [PMID: 16359643 DOI: 10.1016/j.bcp.2005.11.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2005] [Revised: 11/02/2005] [Accepted: 11/10/2005] [Indexed: 10/25/2022]
Abstract
Microbial resistance necessitates the search for new targets and new antibiotics. However, it is likely that resistance problems will eventually threaten these new products and it may, therefore, be instructive to review the successful employment of beta-lactam antibiotic/beta-lactamase inhibitor combinations to combat penicillin resistance. These combination drugs have proven successful for more than two decades, with inhibitor resistance still being relatively rare. The beta-lactamase inhibitors are mechanism-based irreversible inactivators. The ability of the inhibitors to avoid resistance may be due to the structural similarities between the substrate and inhibitor.
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Affiliation(s)
- John D Buynak
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314, USA.
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23
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Li J, Cross JB, Vreven T, Meroueh SO, Mobashery S, Schlegel HB. Lysine carboxylation in proteins: OXA-10 β-lactamase. Proteins 2005; 61:246-57. [PMID: 16121396 DOI: 10.1002/prot.20596] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An increasing number of proteins are being shown to have an N(zeta)-carboxylated lysine in their structures, a posttranslational modification of proteins that proceeds without the intervention of a specific enzyme. The role of the carboxylated lysine in these proteins is typically structural (hydrogen bonding or metal coordination). However, carboxylated lysines in the active sites of OXA-10 and OXA-1 beta-lactamases and the sensor domain of BlaR signal-transducer protein serve in proton transfer events required for the functions of these proteins. These examples demonstrate the utility of this unusual amino acid in acid-base chemistry, in expansion of function beyond those of the 20 standard amino acids. In this study, the ONIOM quantum-mechanical/molecular-mechanical (QM/MM) method is used to study the carboxylation of lysine in the OXA-10 beta-lactamase. Lys-70 and the active site of the OXA-10 beta-lactamase were treated with B3LYP/6-31G(d,p) density functional calculations and the remainder of the enzyme with the AMBER molecular mechanics force field. The barriers for unassisted carboxylation of neutral lysine by carbon dioxide or bicarbonate are high. However, when the reaction with CO2 is catalyzed by a molecule of water in the active site, it is exothermic by about 13 kcal/mol, with a barrier of approximately 14 kcal/mol. The calculations show that the carboxylation and decarboxylation of Lys-70 are likely to be accompanied by deprotonation and protonation of the carbamate, respectively. The analysis may also be relevant for other proteins with carboxylated lysines, a feature that may be more common in nature than previously appreciated.
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Affiliation(s)
- Jie Li
- Department of Chemistry and Institute for Scientific Computing, Wayne State University, Detroit, Michigan 48202, USA
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24
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Fisher JF, Meroueh SO, Mobashery S. Bacterial resistance to beta-lactam antibiotics: compelling opportunism, compelling opportunity. Chem Rev 2005; 105:395-424. [PMID: 15700950 DOI: 10.1021/cr030102i] [Citation(s) in RCA: 684] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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25
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Kershaw NJ, Caines MEC, Sleeman MC, Schofield CJ. The enzymology of clavam and carbapenem biosynthesis. Chem Commun (Camb) 2005:4251-63. [PMID: 16113715 DOI: 10.1039/b505964j] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The enzyme-catalysed reactions involved in formation of the bicyclic clavam and carbapenem nuclei, including beta-amino acid and beta-lactam formation, are discussed and compared with those involved in penicillin and cephalosporin biosynthesis. The common role of unusual oxidation reactions in the biosynthetic pathways and the lack of synthetic reagents available to effect them are highlighted.
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Affiliation(s)
- Nadia J Kershaw
- Department of Chemistry and Oxford Centre for Molecular Sciences, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK
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26
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Orabi AS. Physicochemical Properties of Ampicillin and Amoxicillin as Biologically Active Ligands with Some Alkali Earth, Transition Metal, and Lanthanide Ions in Aqueous and Mixed Solvents at 20, 30, and 40?C. J SOLUTION CHEM 2005. [DOI: 10.1007/s10953-005-2075-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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27
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Venkatesan AM, Agarwal A, Abe T, Ushirogochi H, Yamamura I, Kumagai T, Petersen PJ, Weiss WJ, Lenoy E, Yang Y, Shlaes DM, Ryan JL, Mansour TS. Novel imidazole substituted 6-methylidene-penems as broad-spectrum β-lactamase inhibitors. Bioorg Med Chem 2004; 12:5807-17. [PMID: 15498657 DOI: 10.1016/j.bmc.2004.08.039] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Revised: 08/20/2004] [Accepted: 08/26/2004] [Indexed: 10/26/2022]
Abstract
Beta-lactamases are serine and metallo-dependent enzymes produced by the bacteria in defense against beta-lactam antibiotics. Production of class-A, class-B, and class-C enzymes by the bacteria make the use of beta-lactam antibiotics ineffective in certain cases. To overcome resistance to beta-lactam antibiotics, several beta-lactamase inhibitors such as clavulanic acid, sulbactam, and tazobactam are widely used in the clinic in combination with beta-lactam antibiotics. However, single point mutations within these enzymes have allowed bacteria to overcome the inhibitory effect of the commercially approved beta-lactamase inhibitors. Although the commercially available beta-lactamase inhibitor/beta-lactam antibiotic combinations are effective against class-A producing bacteria and many extended spectrum beta-lactamase (ESBL's) producing bacteria they are less effective against class-C enzymes expressing bacteria. To circumvent this problem, based on modeling studies several novel imidazole substituted 6-methylidene-penem derivatives were synthesized and tested against various beta-lactamase producing isolates. The present paper deals with the synthesis and structure-activity relationships (SAR) of these compounds.
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28
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Haeggman S, Löfdahl S, Paauw A, Verhoef J, Brisse S. Diversity and evolution of the class A chromosomal beta-lactamase gene in Klebsiella pneumoniae. Antimicrob Agents Chemother 2004; 48:2400-8. [PMID: 15215087 PMCID: PMC434173 DOI: 10.1128/aac.48.7.2400-2408.2004] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the diversity of the chromosomal class A beta-lactamase gene in Klebsiella pneumoniae in order to study the evolution of the gene. A 789-bp portion was sequenced in a panel of 28 strains, representative of three phylogenetic groups, KpI, KpII, and KpIII, recently identified in K. pneumoniae and of different chromosomal beta-lactamase variants previously identified. Three groups of sequences were found, two of them corresponding to the families SHV (pI 7.6) and LEN (pI 7.1), respectively, and one, more heterogeneous, corresponding to a new family that we named OKP (for other K. pneumoniae beta-lactamase). Levels of susceptibility to ampicillin, cefuroxime, cefotaxime, ceftazidime, and aztreonam and inhibition by clavulanic acid were similar in the three groups. One new SHV variant, seven new LEN variants, and four OKP variants were identified. The OKP variants formed two subgroups based on nucleotide sequences, one with pIs of 7.8 and 8.1 and the other with pIs of 6.5 and 7.0. The nucleotide sequences of the housekeeping genes gyrA, coding for subunit A of gyrase, and mdh, coding for malate dehydrogenase, were also determined. Phylogenetic analysis of the three genes studied revealed parallel evolution, with the SHV, OKP, and LEN beta-lactamase families corresponding to the phylogenetic groups KpI, KpII, and KpIII, respectively. This correspondence was fully confirmed for 34 additional strains in PCR assays specific for the three beta-lactamase families. We estimated the time since divergence of the phylogenetic groups KpI and KpIII at between 6 and 28 million years, confirming the ancient presence of the beta-lactamase gene in the genome of K. pneumoniae.
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Affiliation(s)
- S Haeggman
- Swedish Institute for Infectious Disease Control, SE-171 82 Solna, Sweden
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29
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Doucet N, De Wals PY, Pelletier JN. Site-saturation mutagenesis of Tyr-105 reveals its importance in substrate stabilization and discrimination in TEM-1 beta-lactamase. J Biol Chem 2004; 279:46295-303. [PMID: 15326193 DOI: 10.1074/jbc.m407606200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The conserved Class A beta-lactamase active site residue Tyr-105 was substituted by saturation mutagenesis in TEM-1 beta-lactamase from Escherichia coli in order to clarify its role in enzyme activity and in substrate stabilization and discrimination. Minimum inhibitory concentrations were calculated for E. coli cells harboring each Y105X mutant in the presence of various penicillin and cephalosporin antibiotics. We found that only aromatic residues as well as asparagine replacements conferred high in vivo survival rates for all substrates tested. At position 105, the small residues alanine and glycine provide weak substrate discrimination as evidenced by the difference in benzylpenicillin hydrolysis relative to cephalothin, two typical penicillin and cephalosporin antibiotics. Kinetic analyses of mutants of interest revealed that the Y105X replacements have a greater effect on K(m) than k(cat), highlighting the importance of Tyr-105 in substrate recognition. Finally, by performing a short molecular dynamics study on a restricted set of Y105X mutants of TEM-1, we found that the strong aromatic bias observed at position 105 in Class A beta-lactamases is primarily defined by a structural requirement, selecting planar residues that form a stabilizing wall to the active site. The adopted conformation of residue 105 prevents detrimental steric interactions with the substrate molecule in the active site cavity and provides a rationalization for the strong aromatic bias found in nature at this position among Class A beta-lactamases.
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Affiliation(s)
- Nicolas Doucet
- Département de Biochimie and Département de chimie, Université de Montréal, C. P. 6128, Succursale Centre-ville, Montréal, Québec H3C 3J7, Canada
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30
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Fuda C, Suvorov M, Vakulenko SB, Mobashery S. The basis for resistance to beta-lactam antibiotics by penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus. J Biol Chem 2004; 279:40802-6. [PMID: 15226303 DOI: 10.1074/jbc.m403589200] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Penicillin-binding protein 2a (PBP2a) of Staphylococcus aureus is refractory to inhibition by available beta-lactam antibiotics, resulting in resistance to these antibiotics. The strains of S. aureus that have acquired the mecA gene for PBP2a are designated as methicillin-resistant S. aureus (MRSA). The mecA gene was cloned and expressed in Escherichia coli, and PBP2a was purified to homogeneity. The kinetic parameters for interactions of several beta-lactam antibiotics (penicillins, cephalosporins, and a carbapenem) and PBP2a were evaluated. The enzyme manifests resistance to covalent modification by beta-lactam antibiotics at the active site serine residue in two ways. First, the microscopic rate constant for acylation (k2) is attenuated by 3 to 4 orders of magnitude over the corresponding determinations for penicillin-sensitive penicillin-binding proteins. Second, the enzyme shows elevated dissociation constants (Kd) for the non-covalent pre-acylation complexes with the antibiotics, the formation of which ultimately would lead to enzyme acylation. The two factors working in concert effectively prevent enzyme acylation by the antibiotics in vivo, giving rise to drug resistance. Given the opportunity to form the acyl enzyme species in in vitro experiments, circular dichroism measurements revealed that the enzyme undergoes substantial conformational changes in the course of the process that would lead to enzyme acylation. The observed conformational changes are likely to be a hallmark for how this enzyme carries out its catalytic function in cross-linking the bacterial cell wall.
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Affiliation(s)
- Cosimo Fuda
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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31
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Golemi-Kotra D, Meroueh SO, Kim C, Vakulenko SB, Bulychev A, Stemmler AJ, Stemmler TL, Mobashery S. The importance of a critical protonation state and the fate of the catalytic steps in class A beta-lactamases and penicillin-binding proteins. J Biol Chem 2004; 279:34665-73. [PMID: 15152012 PMCID: PMC3371256 DOI: 10.1074/jbc.m313143200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Beta-lactamases and penicillin-binding proteins are bacterial enzymes involved in antibiotic resistance to beta-lactam antibiotics and biosynthetic assembly of cell wall, respectively. Members of these large families of enzymes all experience acylation by their respective substrates at an active site serine as the first step in their catalytic activities. A Ser-X-X-Lys sequence motif is seen in all these proteins, and crystal structures demonstrate that the side-chain functions of the serine and lysine are in contact with one another. Three independent methods were used in this report to address the question of the protonation state of this important lysine (Lys-73) in the TEM-1 beta-lactamase from Escherichia coli. These techniques included perturbation of the pK(a) of Lys-73 by the study of the gamma-thialysine-73 variant and the attendant kinetic analyses, investigation of the protonation state by titration of specifically labeled proteins by nuclear magnetic resonance, and by computational treatment using the thermodynamic integration method. All three methods indicated that the pK(a) of Lys-73 of this enzyme is attenuated to 8.0-8.5. It is argued herein that the unique ground-state ion pair of Glu-166 and Lys-73 of class A beta-lactamases has actually raised the pK(a) of the active site lysine to 8.0-8.5 from that of the parental penicillin-binding protein. Whereas we cannot rule out that Glu-166 might activate the active site water, which in turn promotes Ser-70 for the acylation event, such as proposed earlier, we would like to propose as a plausible alternative for the acylation step the possibility that the ion pair would reconfigure to the protonated Glu-166 and unprotonated Lys-73. As such, unprotonated Lys-73 could promote serine for acylation, a process that should be shared among all active-site serine beta-lactamases and penicillin-binding proteins.
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Affiliation(s)
- Dasantila Golemi-Kotra
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Samy O. Meroueh
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Choonkeun Kim
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Sergei B. Vakulenko
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Alexey Bulychev
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Ann J. Stemmler
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
| | - Timothy L. Stemmler
- Department of Biochemistry and Molecular Biology, Wayne State University, Detroit, Michigan 48202
- To whom correspondence may be addressed: Dept. of Biochemistry and Molecular Biology, Wayne State University, Detroit, MI 48202. Tel.: 313-577-5712; Fax: 313-577-2765;
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556
- To whom correspondence may be addressed: Dept. of Chemistry and Biochemistry, University of Notre Dame, 423 Nieuwland Science Hall, Notre Dame, IN 46556. Tel.: 574-631-2933; Fax: 574-631-6652;
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32
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Cha JY, Ishiwata A, Mobashery S. A novel beta-lactamase activity from a penicillin-binding protein of Treponema pallidum and why syphilis is still treatable with penicillin. J Biol Chem 2004; 279:14917-21. [PMID: 14747460 DOI: 10.1074/jbc.m400666200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Treponema pallidum, the causative agent of syphilis, is sensitive to penicillins. Yet, an abundant membrane-bound protein of this organism, Tp47, turns over penicillins. It is shown herein that the turnover process is a hydrolytic reaction that results in the corresponding penicilloates, products that have their beta-lactam bonds hydrolyzed. This is the reaction of beta-lactamases, bona fide resistance enzymes to beta-lactam antibiotics. Remarkably, the x-ray structure of Tp47 bears no resemblance to any other beta-lactamases or the related penicillin-binding proteins. Furthermore, evidence is presented that the reaction of Tp47 takes place in the absence of the zinc ion and does not involve intermediary acyl enzyme species. Hence, the beta-lactamase activity of Tp47 is the fifth known mechanism for turnover of beta-lactam antibiotics. Tp47 also exhibits a penicillin binding reaction, in the process of which the enzyme is covalently modified in the active site. The two reactions take place in two different active sites, and the events of the beta-lactamase activity are over 2,000-fold more rapid than the penicillin binding reaction. The level of beta-lactamase activity is high and is held back only by a strong product-inhibition component to the catalytic process. If natural selection would result in a mutant variant of Tp47 that overcomes product inhibition for the beta-lactamase activity, a novel bona fide resistance to penicillins will emerge in Treponema, which will be a disconcerting clinical development. The physiological functions of Tp47 are not known, but it is likely that this is at least a bifunctional enzyme involved in the processing of the Treponema peptidoglycan as a substrate.
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Affiliation(s)
- Joo Young Cha
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA.
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33
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References. Antibiotics (Basel) 2003. [DOI: 10.1128/9781555817886.refs] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Abstract
When Bacteria, Archaea, and Eucarya separated from each other, a great deal of evolution had taken place. Only then did extensive diversity arise. The bacteria split off with the new property that they had a sacculus that protected them from their own turgor pressure. The saccular wall of murein (or peptidoglycan) was an effective solution to the osmotic pressure problem, but it then was a target for other life-forms, which created lysoymes and beta-lactams. The beta-lactams, with their four-member strained rings, are effective agents in nature and became the first antibiotic in human medicine. But that is by no means the end of the story. Over evolutionary time, bacteria challenged by beta-lactams evolved countermeasures such as beta-lactamases, and the producing organisms evolved variant beta-lactams. The biology of both classes became evident as the pharmaceutical industry isolated, modified, and produced new chemotherapeutic agents and as the properties of beta-lactams and beta-lactamases were examined by molecular techniques. This review attempts to fit the wall biology of current microbes and their clinical context into the way organisms developed on this planet as well as the changes arising since the work done by Fleming. It also outlines the scientific advances in our understanding of this broad area of biology.
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Affiliation(s)
- Arthur L Koch
- Biology Department, Indiana University, Bloomington, Indiana 47405-6801, USA.
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Abstract
Aminoglycoside antibiotics have had a major impact on our ability to treat bacterial infections for the past half century. Whereas the interest in these versatile antibiotics continues to be high, their clinical utility has been compromised by widespread instances of resistance. The multitude of mechanisms of resistance is disconcerting but also illuminates how nature can manifest resistance when bacteria are confronted by antibiotics. This article reviews the most recent knowledge about the mechanisms of aminoglycoside action and the mechanisms of resistance to these antibiotics.
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Affiliation(s)
- Sergei B Vakulenko
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202, USA
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Golemi-Kotra D, Cha JY, Meroueh SO, Vakulenko SB, Mobashery S. Resistance to beta-lactam antibiotics and its mediation by the sensor domain of the transmembrane BlaR signaling pathway in Staphylococcus aureus. J Biol Chem 2003; 278:18419-25. [PMID: 12591921 DOI: 10.1074/jbc.m300611200] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Staphylococci, a leading cause of infections worldwide, have devised two mechanisms for resistance to beta-lactam antibiotics. One is production of beta-lactamases, hydrolytic resistance enzymes, and the other is the expression of penicillin-binding protein 2a (PBP 2a), which is not susceptible to inhibition by beta-lactam antibiotics. The beta-lactam sensor-transducer (BlaR), an integral membrane protein, binds beta-lactam antibiotics on the cell surface and transduces the information to the cytoplasm, where gene expression is derepressed for both beta-lactamase and penicillin-binding protein 2a. The gene for the sensor domain of the sensor-transducer protein (BlaR(S)) of Staphylococcus aureus was cloned, and the protein was purified to homogeneity. It is shown that beta-lactam antibiotics covalently modify the BlaR(S) protein. The protein was shown to contain the unusual carboxylated lysine that activates the active site serine residue for acylation by the beta-lactam antibiotics. The details of the kinetics of interactions of the BlaR(S) protein with a series of beta-lactam antibiotics were investigated. The protein undergoes acylation by beta-lactam antibiotics with microscopic rate constants (k(2)) of 1-26 s(-1), yet the deacylation process was essentially irreversible within one cell cycle. The protein undergoes a significant conformational change on binding with beta-lactam antibiotics, a process that commences at the preacylation complex and reaches its full effect after protein acylation has been accomplished. These conformational changes are likely to be central to the signal transduction events when the organism is exposed to the beta-lactam antibiotic.
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Affiliation(s)
- Dasantila Golemi-Kotra
- Department of Chemistry, Institute for Drug Design, Wayne State University, Detroit, Michigan 48202-3489, USA
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37
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Meroueh SO, Roblin P, Golemi D, Maveyraud L, Vakulenko SB, Zhang Y, Samama JP, Mobashery S. Molecular dynamics at the root of expansion of function in the M69L inhibitor-resistant TEM beta-lactamase from Escherichia coli. J Am Chem Soc 2002; 124:9422-30. [PMID: 12167037 DOI: 10.1021/ja026547q] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Clavulanate, an inhibitor for beta-lactamases, was the very first inhibitor for an antibiotic resistance enzyme that found clinical utility in 1985. The clinical use of clavulanate and that of sulbactam and tazobactam, which were introduced to the clinic subsequently, has facilitated evolution of a set of beta-lactamases that not only retain their original function as resistance enzymes but also are refractory to inhibition by the inhibitors. This article characterizes the properties of the clinically identified M69L mutant variant of the TEM-1 beta-lactamase from Escherichia coli, an inhibitor-resistant beta-lactamase, and compares it to the wild-type enzyme. The enzyme is as active as the wild-type in turnover of typical beta-lactam antibiotics. Furthermore, many of the parameters for interactions of the inhibitors with the mutant enzyme are largely unaffected. The significant effect of the inhibitor-resistant trait was a relatively modest elevation of the dissociation constant for the formation of the pre-acylation complex. The high-resolution X-ray crystal structure for the M69L mutant variant revealed essentially no alteration of the three-dimensional structure, both for the protein backbone and for the positions of the side chains of the amino acids. It was surmised that the difference in the two enzymes must reside with the dynamic motions of the two proteins. Molecular dynamics simulations of the mutant and wild-type proteins were carried out for 2 ns each. Dynamic cross-correlated maps revealed the collective motions of the two proteins to be very similar, yet the two proteins did not behave identically. Differences in behavior of the two proteins existed in the regions between residues 145-179 and 155-162. Additional calculations revealed that kinetic effects measured experimentally for the dissociation constant for the pre-acylation complex could be mostly attributed to the electrostatic and van der Waals components of the binding free energy. The effects of the mutation on the behavior of the beta-lactamase were subtle, including the differences in the measured dissociation constants that account for the inhibitor-resistant trait. It would appear that nature has selected for incorporation of the most benign alteration in the structure of the wild-type TEM-1 beta-lactamase that is sufficient to give the inhibitor-resistant trait.
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Affiliation(s)
- Samy O Meroueh
- Contribution from the Groupe de Cristallographie Biologique, Institut de Pharmacologie et de Biologie Structurale du CNRS, 205 route de Narbonne, 31077 Toulouse Cedex, France.
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38
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Buynak JD, Vogeti L, Doppalapudi VR, Solomon GM, Chen H. Cephalosporin-derived inhibitors of beta-lactamase. Part 4: The C3 substituent. Bioorg Med Chem Lett 2002; 12:1663-6. [PMID: 12039585 DOI: 10.1016/s0960-894x(02)00205-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
New C3-substituted beta-lactamase inhibitors were prepared and evaluated against representative class A and class C enzymes. It was possible to improve simultaneous inhibitory activity of both classes of serine hydrolase. Other inhibitors showed high selectivity for either the class C cephalosporinases or the class A penicillinases. This represents the first time that cephalosporin-derived inhibitors have demonstrated selectivity for the class A beta-lactamases.
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Affiliation(s)
- John D Buynak
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314, USA.
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39
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Vessillier S, Docquier JD, Rival S, Frere JM, Galleni M, Amicosante G, Rossolini GM, Franceschini N. Overproduction and biochemical characterization of the Chryseobacterium meningosepticum BlaB metallo-beta-lactamase. Antimicrob Agents Chemother 2002; 46:1921-7. [PMID: 12019109 PMCID: PMC127231 DOI: 10.1128/aac.46.6.1921-1927.2002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The BlaB metallo-beta-lactamase of Chryseobacterium meningosepticum CCUG4310 was overproduced in Escherichia coli by means of a T7 promoter-based expression system. The overproducing system, scaled up in a 15-liter fermentor, yielded approximately 10 mg of BlaB protein per liter, mostly released in the culture supernatant. The enzyme was purified by two ion-exchange chromatographic steps with an overall yield of 66%. Analysis of the kinetic parameters revealed efficient activities (k(cat)/K(m) ratios of >10(6) M(-1) s(-1)) toward most penam and carbapenem compounds, with the exception of the 6-alpha-methoxypenam derivative temocillin and of biapenem, which were poorer substrates. Hydrolysis of cephalosporins was overall less efficient, with a remarkable variability that was largely due to variable affinities of the BlaB enzyme for different compounds. BlaB was also able to hydrolyze serine-beta-lactamase inhibitors, including beta-iodopenicillanate, sulbactam and, although less efficiently, tazobactam.
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Affiliation(s)
- Sandrine Vessillier
- Dipartimento di Scienze e Tecnologie Biomediche, Università di L'Aquila, I-67100 L'Aquila, Italy
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40
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Maveyraud L, Golemi-Kotra D, Ishiwata A, Meroueh O, Mobashery S, Samama JP. High-resolution X-ray structure of an acyl-enzyme species for the class D OXA-10 beta-lactamase. J Am Chem Soc 2002; 124:2461-5. [PMID: 11890794 DOI: 10.1021/ja016736t] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Beta-lactamases are resistance enzymes for beta-lactam antibiotics. These enzymes hydrolyze the beta-lactam moieties of these antibiotics, rendering them inactive. Of the four classes of known beta-lactamases, the enzymes of class D are the least understood. We report herein the high-resolution (1.9 A) crystal structure of the class D OXA-10 beta-lactamase inhibited by a penicillanate derivative. The structure provides evidence that the carboxylated Lys-70 (a carbamate) is intimately involved in the mechanism of the enzyme.
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Affiliation(s)
- Laurent Maveyraud
- Groupe de Cristallographie Biologique, Institut de Pharmacologie et de Biologie Structurale du CNRS, 205 route de Narbonne, 31077-Toulouse Cedex, France
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41
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Golemi D, Maveyraud L, Vakulenko S, Samama JP, Mobashery S. Critical involvement of a carbamylated lysine in catalytic function of class D beta-lactamases. Proc Natl Acad Sci U S A 2001; 98:14280-5. [PMID: 11724923 PMCID: PMC64673 DOI: 10.1073/pnas.241442898] [Citation(s) in RCA: 184] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
beta-Lactamases are the resistance enzymes for beta-lactam antibiotics, of which four classes are known. beta-lactamases hydrolyze the beta-lactam moieties of these antibiotics, rendering them inactive. It is shown herein that the class D OXA-10 beta-lactamase depends critically on an unusual carbamylated lysine as the basic residue for both the enzyme acylation and deacylation steps of catalysis. The formation of carbamylated lysine is reversible. Evidence is presented that this enzyme is dimeric and carbamylated in living bacteria. High-resolution x-ray structures for the native enzyme were determined at pH values of 6.0, 6.5, 7.5, and 8.5. Two dimers are present per asymmetric unit. One monomer in each dimer was carbamylated at pH 6.0, whereas all four monomers were fully carbamylated at pH 8.5. At the intermediate pH values, one monomer of each dimer was carbamylated, and the other showed a mixture of carbamylated and non-carbamylated lysines. It would appear that, as the pH increased for the sample, additional lysines were "titrated" by carbamylation. A handful of carbamylated lysines are known from protein crystallographic data, all of which have been attributed roles in structural stabilization (mostly as metal ligands) of the proteins. This paper reports a previously unrecognized role for a noncoordinated carbamylate lysine as a basic residue involved in mechanistic reactions of an enzyme, which indicates another means for expansion of the catalytic capabilities of the amino acids in nature beyond the 20 common amino acids in development of biological catalysts.
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Affiliation(s)
- D Golemi
- Groupe de Cristallographie Biologique, Institut de Pharmacologie et de Biologie Structurale du Centre National de la Recherche Scientifique, 205 Route de Narbonne, 31077-Toulouse Cedex, France
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42
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Hujer AM, Hujer KM, Bonomo RA. Mutagenesis of amino acid residues in the SHV-1 beta-lactamase: the premier role of Gly238Ser in penicillin and cephalosporin resistance. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1547:37-50. [PMID: 11343789 DOI: 10.1016/s0167-4838(01)00164-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The recent availability of the SHV-1 beta-lactamase crystal structure provides a framework for the understanding of the functional role of amino acid residues in this enzyme. To that end, we have constructed by site-directed mutagenesis 18 variants of the SHV beta-lactamase: an extended spectrum group: Gly238Ser, Gly238Ser-Glu240Lys, Asp104Lys-Gly238Ser, Asp104Lys-Thr235Ser-Gly238Ser, Asp179Asn, Arg164His, and Arg164Ser; an inhibitor resistant group: Arg244Ser, Met69Ile, Met69Leu, and Ser130Gly; mutants that are synergistic with those that confer resistance to oxyimino-cephalosporins: Asp104Glu, Asp104Lys, Glu240Lys, and Glu240Gln; and structurally conserved mutants: Thr235Ser, Thr235Ala and Glu166Ala. Among the extended spectrum group the combination of high-level ampicillin and cephalosporin resistance was demonstrated in the Escherichia coli DH10B strains possessing the Gly238Ser mutation: Gly238Ser, Gly238Ser-Glu240Lys, Asp104Lys-Gly238Ser, and Asp104Lys-Thr235Ser-Gly238Ser. Of the inhibitor resistant group, the Ser130Gly mutant was the most resistant to ampicillin/clavulanate. Using a polyclonal anti-SHV antibody, we assayed steady state protein expression levels of the SHV beta-lactamase variants. Mutants with the Gly238Ser substitution were among the most highly expressed. The Gly238Ser substitution resulted in an improved relative k(cat)/K(m) value for cephaloridine and oxyimino-cephalosporins compared to SHV-1 and Met69Ile. In our comparative survey, the Gly238Ser and extended spectrum beta-lactamase variants containing this substitution exhibited the greatest substrate versatility against penicillins and cephalosporins and greatest protein expression. This defines a unique role of Gly238Ser in broad-spectrum beta-lactam resistance in this family of class A beta-lactamases.
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Affiliation(s)
- A M Hujer
- Research Service, Louis Stokes Veterans Affairs Medical Center, OH 44106, USA
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43
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Azucena E, Mobashery S. Aminoglycoside-modifying enzymes: mechanisms of catalytic processes and inhibition. Drug Resist Updat 2001; 4:106-17. [PMID: 11512519 DOI: 10.1054/drup.2001.0197] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The most prevalent mechanism for resistance to aminoglycoside antibiotics is mediated through their enzymatic modification in resistant organisms. Dozens of aminoglycoside-modifying enzymes are known at the gene sequence level, but few have been characterized in the details of their mechanism. This review summarizes the state of knowledge of the best studied of these enzymes, focusing on their catalytic mechanisms and inhibition.
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Affiliation(s)
- E Azucena
- Institute for Drug Design, Departments of Chemistry, Pharmacology and Biochemistry and Molecular Biology, Wayne State University, Detroit, Michigan, USA
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44
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Abstract
Three mechanisms of antimicrobial resistance predominate in bacteria: antibiotic inactivation, target site modification, and altered uptake by way of restricted entry and/or enhanced efflux. Many of these involve enzymes or transport proteins whose activity can be targeted directly in an attemptto compromise resistance and, thus, potentiate antimicrobial activity. Alternatively, novel agents unaffected by these resistance mechanisms can be developed. Given the ongoing challenge posed by antimicrobial resistance in bacteria, targeting resistance in this way may be our best hope at prolonging the antibiotic era.
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Affiliation(s)
- K Poole
- Department of Microbiology and Immunology, Queen's University, Kingston, Ontario, Canada.
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45
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Rossolini GM, Condemi MA, Pantanella F, Docquier JD, Amicosante G, Thaller MC. Metallo-beta-lactamase producers in environmental microbiota: new molecular class B enzyme in Janthinobacterium lividum. Antimicrob Agents Chemother 2001; 45:837-44. [PMID: 11181369 PMCID: PMC90382 DOI: 10.1128/aac.45.3.837-844.2001] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eleven environmental samples from different sources were screened for the presence of metallo-beta-lactamase-producing bacteria by using a selective enrichment medium containing a carbapenem antibiotic and subsequently testing each isolate for production of EDTA-inhibitable carbapenemase activity. A total of 15 metallo-beta-lactamase-producing isolates, including 10 Stenotrophomonas maltophilia isolates, 3 Chryseobacterium spp., one Aeromonas hydrophila isolate, and one Janthinobacterium lividum isolate (a species in which production of metallo-beta-lactamase activity was not previously reported), were obtained from 8 samples. In the J. lividum isolate, named JAC1, production of metallo-beta-lactamase activity was elicited upon exposure to beta-lactams. Screening of a JAC1 genomic library for clones showing a reduced imipenem susceptibility led to the isolation of a metallo-beta-lactamase determinant encoding a new member (named THIN-B) of the highly divergent subclass B3 lineage of metallo-beta-lactamases. THIN-B is most closely related (35.6% identical residues) to the L1 enzyme of S. maltophilia and more distantly related to the FEZ-1 enzyme of Legionella gormanii (27.8% identity) and to the GOB-1 enzyme of Chryseobacterium meningosepticum (24.2% identity). Sequences related to bla(THIN-B), and inducible production of metallo-beta-lactamase activity, were also detected in the J. lividum type strain DSM1522. Expression of the bla(THIN-B) gene in Escherichia coli resulted in decreased susceptibility to several beta-lactams, including penicillins, cephalosporins (including cephamycins and oxyimino cephalosporins), and carbapenems, revealing a broad substrate specificity of the enzyme. The results of this study indicated that metallo-beta-lactamase-producing bacteria are widespread in the environment and identified a new molecular class B enzyme in the environmental species J. lividum.
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Affiliation(s)
- G M Rossolini
- Dipartimento di Biologia Molecolare, Sez. di Microbiologia, Università di Siena, 53100 Siena, Italy.
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46
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Lee W, McDonough MA, Kotra L, Li ZH, Silvaggi NR, Takeda Y, Kelly JA, Mobashery S. A 1.2-A snapshot of the final step of bacterial cell wall biosynthesis. Proc Natl Acad Sci U S A 2001; 98:1427-31. [PMID: 11171967 PMCID: PMC29273 DOI: 10.1073/pnas.98.4.1427] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The cell wall imparts structural strength and shape to bacteria. It is made up of polymeric glycan chains with peptide branches that are cross-linked to form the cell wall. The cross-linking reaction, catalyzed by transpeptidases, is the last step in cell wall biosynthesis. These enzymes are members of the family of penicillin-binding proteins, the targets of beta-lactam antibiotics. We report herein the structure of a penicillin-binding protein complexed with a cephalosporin designed to probe the mechanism of the cross-linking reaction catalyzed by transpeptidases. The 1.2-A resolution x-ray structure of this cephalosporin bound to the active site of the bifunctional serine type D-alanyl-D-alanine carboxypeptidase/transpeptidase (EC ) from Streptomyces sp. strain R61 reveals how the two peptide strands from the polymeric substrates are sequestered in the active site of a transpeptidase. The structure of this complex provides a snapshot of the enzyme and the bound cell wall components poised for the final and critical cross-linking step of cell wall biosynthesis.
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Affiliation(s)
- W Lee
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269-3125, USA
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47
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Bulychev A, Bellettini JR, O'Brien M, Crocker PJ, Samama JP, Miller MJ, Mobashery S. N-Sulfonyloxy-β-lactam Inhibitors for β-Lactamases. Tetrahedron 2000. [DOI: 10.1016/s0040-4020(00)00427-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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48
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Wright GD. Resisting resistance: new chemical strategies for battling superbugs. CHEMISTRY & BIOLOGY 2000; 7:R127-32. [PMID: 10873842 DOI: 10.1016/s1074-5521(00)00126-5] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
As microbes become increasingly resistant to antibiotics, and in many cases to several drugs simultaneously, the search is on to find new therapies. One method to combat resistance is to use inhibitors of resistance mechanisms to potentiate existing antibiotics. Recent efforts are encouraging and highlight the importance of research at the chemistry-microbiology interface in developing new approaches to tackle resistance.
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Affiliation(s)
- G D Wright
- Department of Biochemistry, Antimicrobial Research Centre, McMaster University, ON, L8N 3Z5, Canada.
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49
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Buynak JD, Doppalapudi VR, Adam G. The synthesis and evaluation of 3-substituted-7-(alkylidene)cephalosporin sulfones as beta-lactamase inhibitors. Bioorg Med Chem Lett 2000; 10:853-7. [PMID: 10853646 DOI: 10.1016/s0960-894x(00)00098-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A series of 3-substituted-7-(alkylidene)cephaloporin sulfones were prepared and evaluated as inhibitors of representative class A and class C serine beta-lactamase. Appropriate substituents resulted in a 1000-fold improvement in the inhibition of the class A enzymes and a simultaneous 20-fold improvement in the inhibition of class C. These new compounds have achieved the goal of creating broad scale inhibitors in the cephalosporin series.
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Affiliation(s)
- J D Buynak
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314, USA.
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50
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Abstract
Two discovery approaches directed to addressing the problem of increasing bacterial resistance are described. The first is a program to build activity against methicillin-resistant Staphylococcus aureus (MRSA) into the cephalosporin class of antibacterials, by enhancing affinity for PBP2a, the penicillin-binding protein responsible for this resistance. Through stepwise improvement in potency, human serum binding, solubility, and betalactamase stability, a stable of new compounds with excellent potential as anti-MRSA agents was realized. From this set was chosen MC-02, 479 (RWJ-54428), which is now undergoing extensive preclinical evaluation. The second approach explores the uridyl peptide family of antibiotics, inhibitors of bacterial translocase (mraY), whose members include the pacidamycins, mureidomycins, and napsamycins. Access to a diverse set of analogs by total synthesis was catalyzed by the discovery that hydrogenation of the 4'-exoenamidofuranosyl moiety causes no loss in biological activity. Indepth exploration of SAR required (1) establishment of the absolute stereochemistry of the central diaminobutyric acid (DABA) moiety and (2) determination of the stereochemistry of the 4'-substituent on the deoxyfuranose unit. The former was accomplished by comparison of DABA derived from degradation of a natural product pacidamycin with a sample synthesized from L-threonine. The biological activity of one member of a synthesized library of possible stereoisomers of the natural product established the absolute stereochemistry of the remaining centers. A variety of analogs of the natural product were prepared utilizing the synthetic methods developed, and their biological activities provide important insights into the specificity and spectrum of the antibiotic class.
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Affiliation(s)
- V J Lee
- Microcide Pharmaceuticals, Inc., Mountain View, California 94043, USA.
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