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Nichols WW, Bradford PA, Lahiri SD, Stone GG. The primary pharmacology of ceftazidime/avibactam: in vitro translational biology. J Antimicrob Chemother 2022; 77:2321-2340. [PMID: 35665807 DOI: 10.1093/jac/dkac171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Previous reviews of ceftazidime/avibactam have focused on in vitro molecular enzymology and microbiology or the clinically associated properties of the combination. Here we take a different approach. We initiate a series of linked reviews that analyse research on the combination that built the primary pharmacology data required to support the clinical and business risk decisions to perform randomized controlled Phase 3 clinical trials, and the additional microbiological research that was added to the above, and the safety and chemical manufacturing and controls data, that constituted successful regulatory licensing applications for ceftazidime/avibactam in multiple countries, including the USA and the EU. The aim of the series is to provide both a source of reference for clinicians and microbiologists to be able to use ceftazidime/avibactam to its best advantage for patients, but also a case study of bringing a novel β-lactamase inhibitor (in combination with an established β-lactam) through the microbiological aspects of clinical development and regulatory applications, updated finally with a review of resistance occurring in patients under treatment. This first article reviews the biochemistry, structural biology and basic microbiology of the combination, showing that avibactam inhibits the great majority of serine-dependent β-lactamases in Enterobacterales and Pseudomonas aeruginosa to restore the in vitro antibacterial activity of ceftazidime. Translation to efficacy against infections in vivo is reviewed in the second co-published article, Nichols et al. (J Antimicrob Chemother 2022; dkac172).
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Giedraitiene A, Pereckaite L, Bredelyte-Gruodiene E, Virgailis M, Ciapiene I, Tatarunas V. CTX-M-producing Escherichia coli strains: resistance to temocillin, fosfomycin, nitrofurantoin and biofilm formation. Future Microbiol 2022; 17:789-802. [PMID: 35549350 DOI: 10.2217/fmb-2021-0202] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Aim: ESBL-producing and bacterial biofilms-forming Escherichia coli are associated with antimicrobial treatment failure. This study aimed to investigate the phenotypic resistance mechanisms of CTX-M E. coli against old antibiotics - cell wall synthesis inhibitors temocillin, nitrofurantoin and fosfomycin. Materials & Methods: Susceptibility to old antibiotics testing was performed using disk diffusion method, biofilm formation was evaluated spectrophotometrically, and PCR was used for the determination of CTX-M type. Results & conclusion: Temocillin was active against nearly 93%, nitrofurantoin and fosfomycin, respectively, 91.7% and 98.6% of tested E. coli. Thus, it demonstrated to be a good alternative therapeutic option against ESBL infections. Bacteria resistant to old antibiotics had CTX-M-15 or CTX-M-15, TEM-1 and OXA-1 combinations. No significant association was found between CTX-M E. coli resistance to temocillin, nitrofurantoin and fosfomycin; however, the level of biofilm formation was found as not affected by the type of CTX-M β-lactamases.
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Affiliation(s)
- Agne Giedraitiene
- Institute of Microbiology & Virology, Lithuanian University of Health Sciences, Kaunas, LT-50162, Lithuania
| | - Laura Pereckaite
- Department of Laboratory Medicine, Lithuanian University of Health Sciences, Kaunas, LT-50161, Lithuania
| | | | - Marius Virgailis
- Institute of Microbiology & Virology, Lithuanian University of Health Sciences, Kaunas, LT-50162, Lithuania
| | - Ieva Ciapiene
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, LT-50161, Lithuania
| | - Vacis Tatarunas
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, LT-50161, Lithuania
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Understanding the molecular interactions of inhibitors against Bla1 beta-lactamase towards unraveling the mechanism of antimicrobial resistance. Int J Biol Macromol 2021; 177:337-350. [PMID: 33582216 DOI: 10.1016/j.ijbiomac.2021.02.069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 11/24/2022]
Abstract
This study evaluated the inhibitory potential of various beta-lactamase inhibitors such as mechanism-based inhibitors (MBIs), carbapenems, monobactam, and non-beta-lactam inhibitors against Bla1, a class-A beta-lactamase encoded by Bacillus anthracis. The binding potential of different inhibitors was estimated using competitive kinetic assay, isothermal titration calorimetry, and Biolayer interferometry. We observed that tazobactam has better inhibition among other MBIs with a characteristics inhibition dissociation constant of 0.51 ± 0.13 μM. Avibactam was also identified as good inhibitor with an inhibition efficiency of 0.6 ± 0.04 μM. All the MBIs (KD = 1.90E-04 M, 2.05E-05 M, 3.55E-04 M for clavulanate, sulbactam and tazobactam) showed significantly better binding potential than carbapenems (KD = 1.02E-03 M, 2.74E-03 M, 1.24E-03 M for ertapenem, imipenem and biapenem respectively). Molecular dynamics simulations were carried out using Bla1-inhibitor complexes to understand the dynamics and stability. The minimum inhibitory concentration (MIC) was carried out by taking various substrates and inhibitors, and later it was followed by cell viability assay. Together, our study helps develop a proper understanding of Bla1 beta-lactamase and its interaction with inhibitory molecules. This study would facilitate comprehending the catalytic divergence of beta-lactamases and the newly emergent resistant strains, focusing on the new generation of therapeutics being less prone to antimicrobial resistance.
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Abstract
Temocillin, a 6-α-methoxy derivative of ticarcillin, is a forgotten antibiotic that has recently been rediscovered, and issues about clinical breakpoints and optimal therapeutic regimens are still ongoing. Temocillin spectrum is almost restricted to Enterobacteriaceae. The addition of the α-methoxy moiety on ticarcillin confers resistance to hydrolysis by Ambler classes A and C β-lactamases (extended spectrum β-lactamases, Klebsiella pneumoniae carbapenemase and AmpC hyperproduced enzymes). Temocillin is bactericidal, and the effect of inoculum size on its activity is relatively mild. The proportion of spontaneous resistant mutants in vitro to temocillin is low, as found in vivo. After intravenous infusion, temocillin showed a prolonged elimination half-life of approximately 5 h. The percentage of protein binding of temocillin is high (approximately 80%), and is concentration-dependent. Temocillin clearance is mainly renal, and urinary recovery is high, ranging from 72 to 82% after 24 h. Furthermore, the penetration of temocillin into bile and peritoneal fluid is high, but poor into cerebrospinal fluid. The cumulative percentage of a 24-h period during which the free drug concentration exceeds the minimum inhibitory concentration (fT > MIC) at steady-state pharmacokinetic conditions seems to be the best pharmacokinetic/pharmacodynamic (PK/PD) index correlating with temocillin efficacy. An fT > MIC of 40-50% is associated with antibacterial effect and survival in vivo. Monte Carlo simulations performed in critically ill patients showed that the 2 g every 12 h and 2 g every 8 h regimens provide a 95% probability of target attainment of 40% fT > MIC up to an MIC of 8 mg/L. In less severely ill patients or in specific foci of infection, such as urinary tract infection, a 4 g daily regimen should be adequate for strains with temocillin MIC up to 16 mg/L. Data regarding actual wild-type MIC distribution, clinical efficacy, PK profiling in volunteers or patients, and PD targets are scarce, and further studies are required to support appropriate dosing recommendations and determination of clinical breakpoints.
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Affiliation(s)
- Kevin Alexandre
- Infectious Diseases Department, Rouen University Hospital, GRAM (EA2656), Rouen, France
| | - Bruno Fantin
- Univ. Paris Diderot, IAME, UMR 1137, Sorbonne Paris Cité, 75018, Paris, France.
- Service de Médecine Interne, Hôpital Beaujon, AP-HP, 100 boulevard du Général Leclerc, 92110, Clichy, France.
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Docquier JD, Mangani S. An update on β-lactamase inhibitor discovery and development. Drug Resist Updat 2017; 36:13-29. [PMID: 29499835 DOI: 10.1016/j.drup.2017.11.002] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 11/01/2017] [Accepted: 11/03/2017] [Indexed: 11/27/2022]
Abstract
Antibiotic resistance, and the emergence of pan-resistant clinical isolates, seriously threatens our capability to treat bacterial diseases, including potentially deadly hospital-acquired infections. This growing issue certainly requires multiple adequate responses, including the improvement of both diagnosis methods and use of antibacterial agents, and obviously the development of novel antibacterial drugs, especially active against Gram-negative pathogens, which represent an urgent medical need. Considering the clinical relevance of both β-lactam antibiotics and β-lactamase-mediated resistance, the discovery and development of combinations including a β-lactamase inhibitor seems to be particularly attractive, despite being extremely challenging due to the enormous diversity, both structurally and mechanistically, of the potential β-lactamase targets. This review will cover the evolution of currently available β-lactamase inhibitors along with the most recent research leading to new β-lactamase inhibitors of potential clinical interest or already in the stage of clinical development.
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Affiliation(s)
- Jean-Denis Docquier
- Department of Medical Biotechnology, University of Siena, Viale Bracci 16, 53100 Siena, Italy.
| | - Stefano Mangani
- Department of Biotechnology, Chemistry and Pharmacy, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy.
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Kandil H, Cramp E, Vaghela T. Trends in Antibiotic Resistance in Urologic Practice. Eur Urol Focus 2016; 2:363-373. [PMID: 28723468 DOI: 10.1016/j.euf.2016.09.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 09/16/2016] [Indexed: 10/20/2022]
Abstract
CONTEXT The significant global upsurge in antimicrobial resistance, particularly among Enterobacteriaceae, represents a serious threat to health care systems. The implications for urologic practice are of particular concern. OBJECTIVE To review trends in antibiotic resistance in urologic practice. EVIDENCE ACQUISITION We report current European trends of resistance in Gram-negative uropathogens. EVIDENCE SYNTHESIS In addition to β-lactam resistance, Gram-negative pathogens are often resistant to multiple drug classes, including aminoglycosides, fluoroquinolones, and carbapenems, commonly used to treat urologic infections. Interest is renewed in old antibiotics, and several new antibiotics are in the pipeline to meet the challenge of treating these infections. In this review, we summarise emerging trends in antimicrobial resistance and its impact on urologic practice. We also review current guidelines on the treatment and prevention of urologic infections with these organisms, and some key antibiotics in the era of resistance. CONCLUSIONS Increasing antimicrobial resistance represents a challenge to urologic practice for both treatment and prophylaxis. Antibiotic choice should be determined according to risk factors for multidrug resistance. Good knowledge of the local microbial prevalence and resistance profile is required to guide antimicrobial therapy. PATIENT SUMMARY Antimicrobial resistance represents a challenge in urology. We summarise emerging trends in antimicrobial resistance and review current guidelines on the treatment and prevention of urologic infections, as well as some key antibiotics in the era of resistance.
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Affiliation(s)
- Hala Kandil
- Microbiology Department, West Hertfordshire Hospitals NHS Trust, Watford, UK
| | - Emma Cramp
- Pharmacy Department, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - Tejal Vaghela
- Pharmacy Department, West Hertfordshire Hospitals NHS Trust, Watford, UK.
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Makena A, van Berkel SS, Lejeune C, Owens RJ, Verma A, Salimraj R, Spencer J, Brem J, Schofield CJ. Chromophore-Linked Substrate (CLS405): Probing Metallo-β-Lactamase Activity and Inhibition. ChemMedChem 2013; 8:1923-9. [DOI: 10.1002/cmdc.201300350] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Indexed: 12/12/2022]
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Biochemical characterization of CTX-M-15 from Enterobacter cloacae and designing a novel non-β-lactam-β-lactamase inhibitor. PLoS One 2013; 8:e56926. [PMID: 23437273 PMCID: PMC3578935 DOI: 10.1371/journal.pone.0056926] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 01/16/2013] [Indexed: 11/19/2022] Open
Abstract
The worldwide dissemination of CTX-M type β-lactamases is a threat to human health. Previously, we have reported the spread of blaCTX-M-15 gene in different clinical strains of Enterobacteriaceae from the hospital settings of Aligarh in north India. In view of the varying resistance pattern against cephalosporins and other β-lactam antibiotics, we intended to understand the correlation between MICs and catalytic activity of CTX-M-15. In this study, steady-state kinetic parameters and MICs were determined on E. coli DH5α transformed with blaCTX-M-15 gene that was cloned from Enterobacter cloacae (EC-15) strain of clinical background. The effect of conventional β-lactamase inhibitors (clavulanic acid, sulbactam and tazobactam) on CTX-M-15 was also studied. We have found that tazobactam is the best among these inhibitors against CTX-M-15. The inhibition characteristic of tazobactam is defined by its very low IC50 value (6 nM), high affinity (Ki = 0.017 µM) and better acylation efficiency (k+2/K′ = 0.44 µM−1s−1). It forms an acyl-enzyme covalent complex, which is quite stable (k+3 = 0.0057 s−1). Since increasing resistance has been reported against conventional β-lactam antibiotic-inhibitor combinations, we aspire to design a non-β-lactam core containing β-lactamase inhibitor. For this, we screened ZINC database and performed molecular docking to identify a potential non-β-lactam based inhibitor (ZINC03787097). The MICs of cephalosporin antibiotics in combination with this inhibitor gave promising results. Steady-state kinetics and molecular docking studies showed that ZINC03787097 is a reversible inhibitor which binds non-covalently to the active site of the enzyme through hydrogen bonds and hydrophobic interactions. Though, it’s IC50 (180 nM) is much higher than tazobactam, it has good affinity for CTX-M-15 (Ki = 0.388 µM). This study concludes that ZINC03787097 compound can be used as seed molecule to design more efficient non-β-lactam containing β-lactamase inhibitor that could evade pre-existing bacterial resistance mechanisms.
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Ehmann DE, Jahić H, Ross PL, Gu RF, Hu J, Kern G, Walkup GK, Fisher SL. Avibactam is a covalent, reversible, non-β-lactam β-lactamase inhibitor. Proc Natl Acad Sci U S A 2012; 109:11663-8. [PMID: 22753474 PMCID: PMC3406822 DOI: 10.1073/pnas.1205073109] [Citation(s) in RCA: 374] [Impact Index Per Article: 31.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Avibactam is a β-lactamase inhibitor that is in clinical development, combined with β-lactam partners, for the treatment of bacterial infections comprising gram-negative organisms. Avibactam is a structural class of inhibitor that does not contain a β-lactam core but maintains the capacity to covalently acylate its β-lactamase targets. Using the TEM-1 enzyme, we characterized avibactam inhibition by measuring the on-rate for acylation and the off-rate for deacylation. The deacylation off-rate was 0.045 min(-1), which allowed investigation of the deacylation route from TEM-1. Using NMR and MS, we showed that deacylation proceeds through regeneration of intact avibactam and not hydrolysis. Other than TEM-1, four additional clinically relevant β-lactamases were shown to release intact avibactam after being acylated. We showed that avibactam is a covalent, slowly reversible inhibitor, which is a unique mechanism of inhibition among β-lactamase inhibitors.
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Affiliation(s)
- David E Ehmann
- Infection Innovative Medicines Unit, AstraZeneca Research & Development Boston, Waltham, MA 02451, USA.
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Power P, Mercuri P, Herman R, Kerff F, Gutkind G, Dive G, Galleni M, Charlier P, Sauvage E. Novel fragments of clavulanate observed in the structure of the class A -lactamase from Bacillus licheniformis BS3. J Antimicrob Chemother 2012; 67:2379-87. [DOI: 10.1093/jac/dks231] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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11
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Dubois D, Baron O, Cougnoux A, Delmas J, Pradel N, Boury M, Bouchon B, Bringer MA, Nougayrède JP, Oswald E, Bonnet R. ClbP is a prototype of a peptidase subgroup involved in biosynthesis of nonribosomal peptides. J Biol Chem 2011; 286:35562-35570. [PMID: 21795676 DOI: 10.1074/jbc.m111.221960] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The pks genomic island of Escherichia coli encodes polyketide (PK) and nonribosomal peptide (NRP) synthases that allow assembly of a putative hybrid PK-NRP compound named colibactin that induces DNA double-strand breaks in eukaryotic cells. The pks-encoded machinery harbors an atypical essential protein, ClbP. ClbP crystal structure and mutagenesis experiments revealed a serine-active site and original structural features compatible with peptidase activity, which was detected by biochemical assays. Ten ClbP homologs were identified in silico in NRP genomic islands of closely and distantly related bacterial species. All tested ClbP homologs were able to complement a clbP-deficient E. coli mutant. ClbP is therefore a prototype of a new subfamily of extracytoplasmic peptidases probably involved in the maturation of NRP compounds. Such peptidases will be powerful tools for the manipulation of NRP biosynthetic pathways.
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Affiliation(s)
- Damien Dubois
- Laboratoire de Bactériologie Clinique, Centre Hospitalier de Clermont-Ferrand, Clermont-Ferrand F-63003, France; Institut National de Recherche Agronomique, Clermont Université, JE 2526 Université d'Auvergne, Unité Sous Contrat 2018, Clermont-Ferrand F-63001, France
| | - Olivier Baron
- INSERM U1043, Toulouse F-31076, France; Centre National de Recherche Scientifique, U5282, Toulouse F-31076, France; Institut National de Recherche Agronomique, Unité Sous Contrat, Toulouse F-31076, France; Université Paul Sabatier-Toulouse III, Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31076, France; Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse F-31059, France
| | - Antony Cougnoux
- Institut National de Recherche Agronomique, Clermont Université, JE 2526 Université d'Auvergne, Unité Sous Contrat 2018, Clermont-Ferrand F-63001, France
| | - Julien Delmas
- Laboratoire de Bactériologie Clinique, Centre Hospitalier de Clermont-Ferrand, Clermont-Ferrand F-63003, France; Institut National de Recherche Agronomique, Clermont Université, JE 2526 Université d'Auvergne, Unité Sous Contrat 2018, Clermont-Ferrand F-63001, France
| | - Nathalie Pradel
- Institut National de Recherche Agronomique, Clermont Université, JE 2526 Université d'Auvergne, Unité Sous Contrat 2018, Clermont-Ferrand F-63001, France
| | - Michèle Boury
- INSERM U1043, Toulouse F-31076, France; Centre National de Recherche Scientifique, U5282, Toulouse F-31076, France; Institut National de Recherche Agronomique, Unité Sous Contrat, Toulouse F-31076, France; Université Paul Sabatier-Toulouse III, Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31076, France
| | | | - Marie-Agnès Bringer
- Institut National de Recherche Agronomique, Clermont Université, JE 2526 Université d'Auvergne, Unité Sous Contrat 2018, Clermont-Ferrand F-63001, France
| | - Jean-Philippe Nougayrède
- INSERM U1043, Toulouse F-31076, France; Centre National de Recherche Scientifique, U5282, Toulouse F-31076, France; Institut National de Recherche Agronomique, Unité Sous Contrat, Toulouse F-31076, France; Université Paul Sabatier-Toulouse III, Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31076, France
| | - Eric Oswald
- INSERM U1043, Toulouse F-31076, France; Centre National de Recherche Scientifique, U5282, Toulouse F-31076, France; Institut National de Recherche Agronomique, Unité Sous Contrat, Toulouse F-31076, France; Université Paul Sabatier-Toulouse III, Centre de Physiopathologie de Toulouse Purpan, Toulouse F-31076, France; Centre Hospitalier Universitaire de Toulouse, Hôpital Purpan, Service de Bactériologie-Hygiène, Toulouse F-31059, France.
| | - Richard Bonnet
- Laboratoire de Bactériologie Clinique, Centre Hospitalier de Clermont-Ferrand, Clermont-Ferrand F-63003, France; Institut National de Recherche Agronomique, Clermont Université, JE 2526 Université d'Auvergne, Unité Sous Contrat 2018, Clermont-Ferrand F-63001, France.
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12
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Drawz SM, Babic M, Bethel CR, Taracila M, Distler AM, Ori C, Caselli E, Prati F, Bonomo RA. Inhibition of the class C beta-lactamase from Acinetobacter spp.: insights into effective inhibitor design. Biochemistry 2010; 49:329-40. [PMID: 19925018 DOI: 10.1021/bi9015988] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The need to develop beta-lactamase inhibitors against class C cephalosporinases of Gram-negative pathogens represents an urgent clinical priority. To respond to this challenge, five boronic acid derivatives, including a new cefoperazone analogue, were synthesized and tested against the class C cephalosporinase of Acinetobacter baumannii [Acinetobacter-derived cephalosporinase (ADC)]. The commercially available carbapenem antibiotics were also assayed. In the boronic acid series, a chiral cephalothin analogue with a meta-carboxyphenyl moiety corresponding to the C(3)/C(4) carboxylate of beta-lactams showed the lowest K(i) (11 +/- 1 nM). In antimicrobial susceptibility tests, this cephalothin analogue lowered the ceftazidime and cefotaxime minimum inhibitory concentrations (MICs) of Escherichia coli DH10B cells carrying bla(ADC) from 16 to 4 microg/mL and from 8 to 1 microg/mL, respectively. On the other hand, each carbapenem exhibited a K(i) of <20 microM, and timed electrospray ionization mass spectrometry (ESI-MS) demonstrated the formation of adducts corresponding to acyl-enzyme intermediates with both intact carbapenem and carbapenem lacking the C(6) hydroxyethyl group. To improve our understanding of the interactions between the beta-lactamase and the inhibitors, we constructed models of ADC as an acyl-enzyme intermediate with (i) the meta-carboxyphenyl cephalothin analogue and (ii) the carbapenems, imipenem and meropenem. Our first model suggests that this chiral cephalothin analogue adopts a novel conformation in the beta-lactamase active site. Further, the addition of the substituent mimicking the cephalosporin dihydrothiazine ring may significantly improve affinity for the ADC beta-lactamase. In contrast, the ADC-carbapenem models offer a novel role for the R(2) side group and also suggest that elimination of the C(6) hydroxyethyl group by retroaldolic reaction leads to a significant conformational change in the acyl-enzyme intermediate. Lessons from the diverse mechanisms and structures of the boronic acid derivatives and carbapenems provide insights for the development of new beta-lactamase inhibitors against these critical drug resistance targets.
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Affiliation(s)
- Sarah M Drawz
- Department of Pathology, Case Western Reserve UniversitySchool of Medicine, Cleveland, Ohio 44106, USA
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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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14
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Chang CF, Ho CW, Wu CY, Chao TA, Wong CH, Lin CH. Discovery of picomolar slow tight-binding inhibitors of alpha-fucosidase. ACTA ACUST UNITED AC 2005; 11:1301-6. [PMID: 15380190 DOI: 10.1016/j.chembiol.2004.07.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2004] [Revised: 06/27/2004] [Accepted: 07/14/2004] [Indexed: 11/26/2022]
Abstract
Glycosidase inhibitors have shown great medicinal and pharmaceutical values as exemplified by the therapeutic treatment of influenza virus and non-insulin-dependent diabetes. We herein report the discovery of picomolar slow tight-binding inhibitors 2-5 against the alpha-fucosidase from Corynebacterium sp. by a rapid screening for an optimal aglycon attached to 1-aminomethyl fuconojirimycin (1). The time-dependent inhibition displays the progressive tightening of enzyme-inhibitor complex from a low nanomolar K(i) to picomolar K(i)* value. Particularly compound 2 with a K(i)* of 0.46 pM represents the most potent glycosidase inhibitor to date. The effect of compound 3 on the intrinsic fluorescence of alpha-fucosidase is both time- and concentration-dependent in a saturation-type manner, which is consistent with the initial formation of a rapid equilibrium complex of enzyme and inhibitor (E.I), followed by the slower formation of a tightly bound enzyme-inhibitor complex (E.I*). The binding affinity increases 3.5 x 10(4)-fold from 1 (K(i) = 16.3 nM) to 2 (K(i)* = 0.46 pM). This work clearly demonstrates the effectiveness of our combinatorial approach leading to the rapid discovery of potent inhibitors.
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Affiliation(s)
- Chuan-Fa Chang
- The Genomic Research Center and Institute of Biological Chemistry, Academia Sinica, No. 128 Academia Road Section 2, Nan-Kang, Taipei 11529, Taiwan
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15
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Vilar M, Galleni M, Solmajer T, Turk B, Frère JM, Matagne A. Kinetic study of two novel enantiomeric tricyclic beta-lactams which efficiently inactivate class C beta-lactamases. Antimicrob Agents Chemother 2001; 45:2215-23. [PMID: 11451677 PMCID: PMC90634 DOI: 10.1128/aac.45.8.2215-2223.2001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A detailed kinetic study of the interaction between two ethylidene derivatives of tricyclic carbapenems, Lek 156 and Lek 157, and representative beta-lactamases and D-alanyl-D-alanine peptidases (DD-peptidases) is presented. Both compounds are very efficient inactivators of the Enterobacter cloacae 908R beta-lactamase, which is usually resistant to inhibition. Preliminary experiments indicate that various extended-spectrum class C beta-lactamases (ACT-1, CMY-1, and MIR-1) are also inactivated. With the E. cloacae 908R enzyme, complete inactivation occurs with a second-order rate constant, k(2)/K', of 2 x 10(4) to 4 x 10(4) M(-1) s(-1), and reactivation is very slow, with a half-life of >1 h. Accordingly, Lek 157 significantly decreases the MIC of ampicillin for E. cloacae P99, a constitutive class C beta-lactamase overproducer. With the other serine beta-lactamases tested, the covalent adducts exhibit a wide range of stabilities, with half-lives ranging from long (>4 h with the TEM-1 class A enzyme), to medium (10 to 20 min with the OXA-10 class D enzyme), to short (0.2 to 0.4 s with the NmcA class A beta-lactamase). By contrast, both carbapenems behave as good substrates of the Bacillus cereus metallo-beta-lactamase (class B). The Streptomyces sp. strain R61 and K15 extracellular DD-peptidases exhibit low levels of sensitivity to both compounds.
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Affiliation(s)
- M Vilar
- Laboratoire d'Enzymologie, Centre for Protein Engineering, University of Liège, Institut de Chimie, Belgium
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16
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Abstract
The use of beta-lactamase inhibitors in combination with a beta-lactamase-susceptible antibiotic is a useful strategy to rescue otherwise good antibiotics from failure. However, recent years have seen a rise in the numbers of beta-lactamases that are insensitive to the available beta-lactamase inhibitors. This review summarizes of the mechanisms of action of the principal types of inhibitors and the ways in which beta-lactamase are thought to develop resistance towards them. Ten general classes of inhibitors are reviewed, especially those of therapeutic importance (clavulanic acid, penam sulfones and carbapenems). Copyright 2000 Harcourt Publishers Ltd.
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Affiliation(s)
- Malcolm G. P. Page
- Pharma Division, Preclinical Research, F. Hoffmann-La Roche Ltd, Basel, CH-4070, Switzerland
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17
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Abdel-Rahman SM, Kearns GL. The beta-lactamase inhibitors: clinical pharmacology and rational application to combination antibiotic therapy. Pediatr Infect Dis J 1998; 17:1185-94. [PMID: 9877381 DOI: 10.1097/00006454-199812000-00026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- S M Abdel-Rahman
- The Children's Mercy Hospital, Department of Pediatrics, University of Missouri-Kansas City, 64108, USA
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18
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Imtiaz U, Billings EM, Knox JR, Mobashery S. A structure-based analysis of the inhibition of class A beta-lactamases by sulbactam. Biochemistry 1994; 33:5728-38. [PMID: 8180199 DOI: 10.1021/bi00185a009] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
From the crystal structure of the Bacillus licheniformis 749/C beta-lactamase, energy-minimized structures for the precatalytic, the acyl-enzyme intermediate, and the acylated linear inactivating species for sulbactam--a clinically useful mechanism-based inactivator for class A beta-lactamases--were generated. The effect of individual Ser-235-Ala and Arg244-Ser point mutations on the inactivation and turnover processes was consistent with the existence of hydrogen bonds between the side chains of these residues and the sulbactam species. The departure of the sulfinate leaving group from the acyl-enzyme intermediate of sulbactam is believed to be a prerequisite for the inactivation process. In order to explore the influence of the leaving group, penicillanic acid (2), penicillanic acid alpha-S-oxide (3), and penicillanic acid beta-S-oxide (4) were synthesized and studied in kinetic experiments with the TEM-1 beta-lactamase. Penicillanic acid is only a substrate, but penicillanic acid S-oxides were both substrates and inactivators for the enzyme. An argument is presented to rationalize these observations on the basis of the leaving ability of thiolate, sulfenate, and sulfinate from the acyl-enzyme intermediates of penicillanic acid (2), the penicillanic acid S-oxides (3 and 4), and sulbactam, respectively. The departure of the leaving group does not appear to be rate limiting in the inactivator process, but is an indispensable component of the irreversible inactivation of the enzyme. Molecular dynamics calculations of the putative inactivating species suggest that Lys-73, Lys-234, and Ser-130 are three likely residues that may be modified in the course of the inactivation chemistry. A discussion is presented of the mechanism of formation of the transiently inhibited enzyme species, which comes about as a consequence of the tautomerization of the double bond of the inactivating iminium moiety. In addition, the mechanistic details presented for sulbactam are compared and contrasted with those of clavulanic acid, another clinically used inactivator for class A beta-lactamases.
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Affiliation(s)
- U Imtiaz
- Department of Chemistry, Wayne State University, Detroit, Michigan 48202
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