1
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Prester A, Perbandt M, Galchenkova M, Oberthuer D, Werner N, Henkel A, Maracke J, Yefanov O, Hakanpää J, Pompidor G, Meyer J, Chapman H, Aepfelbacher M, Hinrichs W, Rohde H, Betzel C. Time-resolved crystallography of boric acid binding to the active site serine of the β-lactamase CTX-M-14 and subsequent 1,2-diol esterification. Commun Chem 2024; 7:152. [PMID: 38969718 PMCID: PMC11226702 DOI: 10.1038/s42004-024-01236-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Accepted: 06/27/2024] [Indexed: 07/07/2024] Open
Abstract
The emergence and spread of antibiotic resistance represent a growing threat to public health. Of particular concern is the appearance of β-lactamases, which are capable to hydrolyze and inactivate the most important class of antibiotics, the β-lactams. Effective β-lactamase inhibitors and mechanistic insights into their action are central in overcoming this type of resistance, and in this context boronate-based β-lactamase inhibitors were just recently approved to treat multidrug-resistant bacteria. Using boric acid as a simplified inhibitor model, time-resolved serial crystallography was employed to obtain mechanistic insights into binding to the active site serine of β-lactamase CTX-M-14, identifying a reaction time frame of 80-100 ms. In a next step, the subsequent 1,2-diol boric ester formation with glycerol in the active site was monitored proceeding in a time frame of 100-150 ms. Furthermore, the displacement of the crucial anion in the active site of the β-lactamase was verified as an essential part of the binding mechanism of substrates and inhibitors. In total, 22 datasets of β-lactamase intermediate complexes with high spatial resolution of 1.40-2.04 Å and high temporal resolution range of 50-10,000 ms were obtained, allowing a detailed analysis of the studied processes. Mechanistic details captured here contribute to the understanding of molecular processes and their time frames in enzymatic reactions. Moreover, we could demonstrate that time-resolved crystallography can serve as an additional tool for identifying and investigating enzymatic reactions.
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Affiliation(s)
- Andreas Prester
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf UKE, Hamburg, Germany
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf UKE, Hamburg, Germany
| | - Markus Perbandt
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
| | | | | | - Nadine Werner
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
- Centre for Integrative Biology, Department of Integrated Structural Biology, Institute of Genetics, Molecular and Cellular Biology, IGBMC, Illkirch, France
| | | | - Julia Maracke
- Center for Free-Electron Laser Science CFEL, DESY, Hamburg, Germany
| | | | | | | | - Jan Meyer
- Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Henry Chapman
- Center for Free-Electron Laser Science CFEL, DESY, Hamburg, Germany
- Hamburg Centre for Ultrafast Imaging CUI, University of Hamburg, Hamburg, Germany
- Department of Physics, University of Hamburg, Hamburg, Germany
| | - Martin Aepfelbacher
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf UKE, Hamburg, Germany
| | - Winfried Hinrichs
- Institute of Biochemistry, University of Greifswald, Greifswald, Germany
| | - Holger Rohde
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf UKE, Hamburg, Germany.
| | - Christian Betzel
- Institute of Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany.
- Hamburg Centre for Ultrafast Imaging CUI, University of Hamburg, Hamburg, Germany.
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2
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Meller A, Kelly D, Smith LG, Bowman GR. Toward physics-based precision medicine: Exploiting protein dynamics to design new therapeutics and interpret variants. Protein Sci 2024; 33:e4902. [PMID: 38358129 PMCID: PMC10868452 DOI: 10.1002/pro.4902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/01/2023] [Accepted: 01/04/2024] [Indexed: 02/16/2024]
Abstract
The goal of precision medicine is to utilize our knowledge of the molecular causes of disease to better diagnose and treat patients. However, there is a substantial mismatch between the small number of food and drug administration (FDA)-approved drugs and annotated coding variants compared to the needs of precision medicine. This review introduces the concept of physics-based precision medicine, a scalable framework that promises to improve our understanding of sequence-function relationships and accelerate drug discovery. We show that accounting for the ensemble of structures a protein adopts in solution with computer simulations overcomes many of the limitations imposed by assuming a single protein structure. We highlight studies of protein dynamics and recent methods for the analysis of structural ensembles. These studies demonstrate that differences in conformational distributions predict functional differences within protein families and between variants. Thanks to new computational tools that are providing unprecedented access to protein structural ensembles, this insight may enable accurate predictions of variant pathogenicity for entire libraries of variants. We further show that explicitly accounting for protein ensembles, with methods like alchemical free energy calculations or docking to Markov state models, can uncover novel lead compounds. To conclude, we demonstrate that cryptic pockets, or cavities absent in experimental structures, provide an avenue to target proteins that are currently considered undruggable. Taken together, our review provides a roadmap for the field of protein science to accelerate precision medicine.
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Affiliation(s)
- Artur Meller
- Department of Biochemistry and Molecular BiophysicsWashington University in St. LouisSt. LouisMissouriUSA
- Medical Scientist Training ProgramWashington University in St. LouisSt. LouisMissouriUSA
- Departments of Biochemistry & Biophysics and BioengineeringUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Devin Kelly
- Departments of Biochemistry & Biophysics and BioengineeringUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Louis G. Smith
- Departments of Biochemistry & Biophysics and BioengineeringUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Gregory R. Bowman
- Departments of Biochemistry & Biophysics and BioengineeringUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
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3
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Sun J, Chikunova A, Boyle AL, Voskamp P, Timmer M, Ubbink M. Enhanced activity against a third-generation cephalosporin by destabilization of the active site of a class A beta-lactamase. Int J Biol Macromol 2023; 250:126160. [PMID: 37549761 DOI: 10.1016/j.ijbiomac.2023.126160] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 07/10/2023] [Accepted: 08/04/2023] [Indexed: 08/09/2023]
Abstract
The β-lactamase BlaC conveys resistance to a broad spectrum of β-lactam antibiotics to its host Mycobacterium tuberculosis but poorly hydrolyzes third-generation cephalosporins, such as ceftazidime. Variants of other β-lactamases have been reported to gain activity against ceftazidime at the cost of the native activity. To understand this trade-off, laboratory evolution was performed, screening for enhanced ceftazidime activity. The variant BlaC Pro167Ser shows faster breakdown of ceftazidime, poor hydrolysis of ampicillin and only moderately reduced activity against nitrocefin. NMR spectroscopy, crystallography and kinetic assays demonstrate that the resting state of BlaC P167S exists in an open and a closed state. The open state is more active in the hydrolysis of ceftazidime. In this state the catalytic residue Glu166, generally believed to be involved in the activation of the water molecule required for deacylation, is rotated away from the active site, suggesting it plays no role in the hydrolysis of ceftazidime. In the closed state, deacylation of the BlaC-ceftazidime adduct is slow, while hydrolysis of nitrocefin, which requires the presence of Glu166 in the active site, is barely affected, providing a structural explanation for the trade-off in activities.
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Affiliation(s)
- Jing Sun
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands
| | - Aleksandra Chikunova
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands
| | - Aimee L Boyle
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands
| | - Patrick Voskamp
- Biophysical Structural Chemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands
| | - Monika Timmer
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands
| | - Marcellus Ubbink
- Macromolecular Biochemistry, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, the Netherlands.
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4
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Rossi MA, Palzkill T, Almeida FCL, Vila AJ. Slow Protein Dynamics Elicits New Enzymatic Functions by Means of Epistatic Interactions. Mol Biol Evol 2022; 39:6711538. [PMID: 36136729 PMCID: PMC9547502 DOI: 10.1093/molbev/msac194] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Protein evolution depends on the adaptation of these molecules to different functional challenges. This occurs by tuning their biochemical, biophysical, and structural traits through the accumulation of mutations. While the role of protein dynamics in biochemistry is well recognized, there are limited examples providing experimental evidence of the optimization of protein dynamics during evolution. Here we report an NMR study of four variants of the CTX-M β-lactamases, in which the interplay of two mutations outside the active site enhances the activity against a cephalosporin substrate, ceftazidime. The crystal structures of these enzymes do not account for this activity enhancement. By using NMR, here we show that the combination of these two mutations increases the backbone dynamics in a slow timescale and the exposure to the solvent of an otherwise buried β-sheet. The two mutations located in this β-sheet trigger conformational changes in loops located at the opposite side of the active site. We postulate that the most active variant explores alternative conformations that enable binding of the more challenging substrate ceftazidime. The impact of the mutations in the dynamics is context-dependent, in line with the epistatic effect observed in the catalytic activity of the different variants. These results reveal the existence of a dynamic network in CTX-M β-lactamases that has been exploited in evolution to provide a net gain-of-function, highlighting the role of alternative conformations in protein evolution.
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Affiliation(s)
- Maria-Agustina Rossi
- Instituto de Biología Molecular y Celular de Rosario (IBR, CONICET-UNR), Ocampo and Esmeralda, Rosario, Argentina
| | - Timothy Palzkill
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, USA,Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, USA
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5
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Evaluation of Tebipenem Hydrolysis by β-Lactamases Prevalent in Complicated Urinary Tract Infections. Antimicrob Agents Chemother 2022; 66:e0239621. [PMID: 35491852 DOI: 10.1128/aac.02396-21] [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: 01/07/2023] Open
Abstract
Tebipenem pivoxil is the first orally available carbapenem antibiotic and has been approved in Japan for treating ear, nose, and throat and respiratory infections in pediatric patients. Its active moiety, tebipenem, has shown potent antimicrobial activity in vitro against clinical isolates of Enterobacterales species from patients with urinary tract infections (UTIs), including those producing extended-spectrum β-lactamases (ESBLs) and/or AmpC β-lactamase. In the present study, tebipenem was tested for stability to hydrolysis by a set of clinically relevant β-lactamases, including TEM-1, AmpC, CTX-M, OXA-48, KPC, and NDM-1 enzymes. In addition, hydrolysis rates of other carbapenems, including imipenem, meropenem, and ertapenem, were determined for comparison. It was found that, similar to other carbapenems, tebipenem was resistant to hydrolysis by TEM-1, CTX-M, and AmpC β-lactamases but was susceptible to hydrolysis by KPC, OXA-48, and NDM-1 enzymes with catalytic efficiency values (kcat/Km) ranging from 0.1 to 2 × 106 M-1s-1. This supports the reported results of antimicrobial activity of tebipenem against ESBL- and AmpC-producing but not carbapenemase-producing Enterobacterales isolates. Considering that CTX-M and AmpC β-lactamases represent the primary determinants of multidrug-resistant complicated UTIs (cUTIs), the stability of tebipenem to hydrolysis by these enzymes supports the utility of its prodrug tebipenem, tebipenem pivoxil hydrobromide (TBP-PI-HBr), as an oral therapy for adult cUTIs.
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6
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Rana C, Rajput S, Behera M, Gautam D, Vikas V, Vats A, Roshan M, Ghorai SM, De S. Global epidemiology of CTX-M-type β-lactam resistance in human and animal. Comp Immunol Microbiol Infect Dis 2022; 86:101815. [DOI: 10.1016/j.cimid.2022.101815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 04/05/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022]
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7
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Structural basis to repurpose boron-based proteasome inhibitors Bortezomib and Ixazomib as β-lactamase inhibitors. Sci Rep 2022; 12:5510. [PMID: 35365689 PMCID: PMC8976068 DOI: 10.1038/s41598-022-09392-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 03/21/2022] [Indexed: 12/23/2022] Open
Abstract
β-lactamases are a major cause of rapidly emerging and spreading antibiotic resistance. Currently β-lactamase inhibitors (BLIs) in clinical use act only on Ambler Class A, C and some class D lactamases. The urgent need to identify new BLIs recently lead to FDA approval of boron-based compounds BLIs, e.g. Vaborbactam. The boron-based proteasome inhibitors Bortezomib and Ixazomib are used in cancer therapy as multiple myeloma drugs but they also bind to Ser-/Thr- proteases. In this study we show the crystal structures of the β-lactamase CTX-M-14 with covalently bound Bortezomib and Ixazomib at high resolutions of 1.3 and 1.1 Å, respectively. Ixazomib is well defined in electron density whereas Bortezomib show some disorder which corresponds to weaker inhibition efficiency observed for Ixazomib. Both inhibitors mimic the deacylation transition state of β-lactam hydrolysis, because they replace the deacylating water molecule. We further investigate differences in binding of Bortezomib/Ixazomib to CTX-M-14 and its target proteases as well as known β-lactamase drugs. Our findings can help to use Bortezomib/Ixazomib as lead compounds for development of new BLIs.
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8
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Yakimowski SB, Teitel Z, Caruso CM. Defence by duplication: The relation between phenotypic glyphosate resistance and EPSPS gene copy number variation in Amaranthus palmeri. Mol Ecol 2021; 30:5328-5342. [PMID: 34662479 DOI: 10.1111/mec.16231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 08/17/2021] [Accepted: 09/08/2021] [Indexed: 12/12/2022]
Abstract
Gene copy number variation (CNV) has been increasingly associated with organismal responses to environmental stress, but we know little about the quantitative relation between CNV and phenotypic variation. In this study we quantify the relation between variation in EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) copy number using digital drop PCR and variation in phenotypic glyphosate resistance in 22 populations of Amaranthus palmeri (Palmer Amaranth), a range-expanding agricultural weed. Overall, we detected a significant positive relation between population mean copy number and resistance. The majority of populations exhibited high glyphosate resistance yet maintained low-resistance individuals, resulting in bimodality in many populations. We also investigated threshold models for the relation between copy number and resistance, and found evidence for a threshold of ~15 EPSPS copies: there was a steep increase in resistance below the threshold, followed by a much shallower increase. Across 924 individuals, as copy number increased the range of variation in resistance decreased, yielding an increasing frequency of high phenotypic resistance individuals. Among populations we detected a decline in variation (s.d.) as mean phenotypic resistance increased from moderate to high, consistent with the prediction that as phenotypic resistance increases in populations, stabilizing selection decreases variation in the trait. Our study demonstrates that populations of A. palmeri can harbour wide variation in EPSPS copy number and phenotypic glyphosate resistance, reflecting the history of, and template for future, resistance evolution.
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Affiliation(s)
| | - Zachary Teitel
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Christina M Caruso
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
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9
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Hu L, Yang X, Yin J, Rong X, Huang X, Yu P, He Z, Liu Y. Combination of AgNPs and Domiphen is Antimicrobial Against Biofilms of Common Pathogens. Int J Nanomedicine 2021; 16:7181-7194. [PMID: 34712048 PMCID: PMC8547768 DOI: 10.2147/ijn.s334133] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/08/2021] [Indexed: 12/05/2022] Open
Abstract
Purpose The aim was to evaluate the antimicrobial potential of AgNPs synthesized with Artemisia argyi leaf extract and investigate the antimicrobial synergistic effects of AgNPs combined with domiphen and provide an efficient and broad-spectrum combination drug strategy. Methods AgNPs synthesized with Artemisia argyi leaf extract were studied using UV–vis spectroscopy, FTIR spectroscopy and particle size analysis. Then, Artemisia argyi leaf extract-synthesized AgNPs and domiphen were tested against Acinetobacter baumannii (ATCC 19606), Staphylococcus aureus (ATCC 6538), Escherichia coli (8099) and Candida albicans (ATCC 10231), respectively. Then, we explore synergistic antimicrobial effect and synergistic anti-biofilm effect through combined drug susceptibility test and combined drug minimum biofilm eradication concentration (MBEC50) test. Results Characteristic absorption bands of AgNPs were found near 430 nm in the UV–vis spectrum. Particle size analysis results revealed that the average particle size of Artemisia argyi leaf extract-synthesized AgNPs was 77.6 nm. Artemisia argyi leaf extract-synthesized AgNPs showed high antimicrobial activity against the above four strains. Minimum inhibitory concentration (MIC) of Artemisia argyi leaf extract-synthesized AgNPs against strains was 1 μg/mL for Acinetobacter baumannii, 2 μg/mL for Staphylococcus aureus, Escherichia coli and Candida albicans. MBEC50 of Artemisia argyi leaf extract-synthesized AgNPs against strains was 2 μg/mL for Acinetobacter baumannii, 4 μg/mL for Staphylococcus aureus, 1/2 μg/mL for Escherichia coli and 2 μg/mL for Candida albicans. The combination of Artemisia argyi leaf extract-synthesized AgNPs and domiphen has synergistic antimicrobial effect and synergistic anti-biofilm effect. Fractional inhibitory concentration (FIC) was ≤0.5. Conclusion Artemisia argyi leaf extract-synthesized AgNPs had antimicrobial activity against the above four strains. The combination of Artemisia argyi leaf extract-synthesized AgNPs and domiphen has synergistic antimicrobial effects to reduce the dosage of each antimicrobial drugs. Artemisia argyi leaf extract-synthesized AgNPs and domiphen have synergistic anti-biofilm effects.
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Affiliation(s)
- Longhao Hu
- Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
| | - Xi Yang
- School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China.,Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
| | - Jing Yin
- Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
| | - Xuan Rong
- Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
| | - Xinlei Huang
- Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
| | - Peiquan Yu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
| | - Zhiqiang He
- Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
| | - Yi Liu
- Department of Biophysics, School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China.,School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China.,Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu, 221004, People's Republic of China
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10
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Kemp MT, Nichols DA, Zhang X, Defrees K, Na I, Renslo AR, Chen Y. Mutation of the conserved Asp-Asp pair impairs the structure, function, and inhibition of CTX-M Class A β-lactamase. FEBS Lett 2021; 595:2981-2994. [PMID: 34704263 DOI: 10.1002/1873-3468.14215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/07/2021] [Accepted: 10/21/2021] [Indexed: 11/07/2022]
Abstract
The Asp233-Asp246 pair is highly conserved in Class A β-lactamases, which hydrolyze β-lactam antibiotics. Here, we characterize its function using CTX-M-14 β-lactamase. The D233N mutant displayed decreased activity that is substrate-dependent, with reductions in kcat /Km ranging from 20% for nitrocefin to 6-fold for cefotaxime. In comparison, the mutation reduced the binding of a known reversible inhibitor by 10-fold. The mutant structures showed movement of the 213-219 loop and the loss of the Thr216-Thr235 hydrogen bond, which was restored by inhibitor binding. Mutagenesis of Thr216 further highlighted its contribution to CTX-M activity. These results demonstrate the importance of the aspartate pair to CTX-M hydrolysis of substrates with bulky side chains, while suggesting increased protein flexibility as a means to evolve drug resistance.
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Affiliation(s)
- M Trent Kemp
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL, USA
| | - Derek A Nichols
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL, USA
| | - Xiujun Zhang
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL, USA
| | - Kyle Defrees
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Insung Na
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL, USA
| | - Adam R Renslo
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Yu Chen
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL, USA
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11
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Miton CM, Buda K, Tokuriki N. Epistasis and intramolecular networks in protein evolution. Curr Opin Struct Biol 2021; 69:160-168. [PMID: 34077895 DOI: 10.1016/j.sbi.2021.04.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/01/2021] [Accepted: 04/21/2021] [Indexed: 12/01/2022]
Abstract
Proteins are molecular machines composed of complex, highly connected amino acid networks. Their functional optimization requires the reorganization of these intramolecular networks by evolution. In this review, we discuss the mechanisms by which epistasis, that is, the dependence of the effect of a mutation on the genetic background, rewires intramolecular interactions to alter protein function. Deciphering the biophysical basis of epistasis is crucial to our understanding of evolutionary dynamics and the elucidation of sequence-structure-function relationships. We featured recent studies that provide insights into the molecular mechanisms giving rise to epistasis, particularly at the structural level. These studies illustrate the convoluted and fascinating nature of the intramolecular networks co-opted by epistasis during the evolution of protein function.
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Affiliation(s)
- Charlotte M Miton
- Michael Smith Laboratories, University of British Columbia, Vancouver, V6T 1Z4, BC, Canada
| | - Karol Buda
- Michael Smith Laboratories, University of British Columbia, Vancouver, V6T 1Z4, BC, Canada
| | - Nobuhiko Tokuriki
- Michael Smith Laboratories, University of British Columbia, Vancouver, V6T 1Z4, BC, Canada.
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12
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Furey IM, Mehta SC, Sankaran B, Hu L, Prasad BVV, Palzkill T. Local interactions with the Glu166 base and the conformation of an active site loop play key roles in carbapenem hydrolysis by the KPC-2 β-lactamase. J Biol Chem 2021; 296:100799. [PMID: 34022225 PMCID: PMC8189571 DOI: 10.1016/j.jbc.2021.100799] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/06/2021] [Accepted: 05/17/2021] [Indexed: 01/05/2023] Open
Abstract
The Klebsiella pneumoniae carbapenemase-2 (KPC-2) is a common source of antibiotic resistance in Gram-negative bacterial infections. KPC-2 is a class A β-lactamase that exhibits a broad substrate profile and hydrolyzes most β-lactam antibiotics including carbapenems owing to rapid deacylation of the covalent acyl-enzyme intermediate. However, the features that allow KPC-2 to deacylate substrates more rapidly than non-carbapenemase enzymes are not clear. The active-site residues in KPC-2 are largely conserved in sequence and structure compared with non-carbapenemases, suggesting that subtle alterations may collectively facilitate hydrolysis of carbapenems. We utilized a nonbiased genetic approach to identify mutants deficient in carbapenem hydrolysis but competent for ampicillin hydrolysis. Subsequent pre–steady-state enzyme kinetics analyses showed that the substitutions slow the rate of deacylation of carbapenems. Structure determination via X-ray diffraction indicated that a F72Y mutant forms a hydrogen bond between the tyrosine hydroxyl group and Glu166, which may lower basicity and impair the activation of the catalytic water for deacylation, whereas several mutants impact the structure of the Q214-R220 active site loop. A T215P substitution lowers the deacylation rate and drastically alters the conformation of the loop, thereby disrupting interactions between the enzyme and the carbapenem acyl-enzyme intermediate. Thus, the environment of the Glu166 general base and the precise placement and conformational stability of the Q214-R220 loop are critical for efficient deacylation of carbapenems by the KPC-2 enzyme. Therefore, the design of carbapenem antibiotics that interact with Glu166 or alter the Q214-R220 loop conformation may disrupt enzyme function and overcome resistance.
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Affiliation(s)
- Ian M Furey
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Shrenik C Mehta
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Banumathi Sankaran
- Department of Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Liya Hu
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston Texas, USA
| | - B V Venkataram Prasad
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston Texas, USA
| | - Timothy Palzkill
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA; Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston Texas, USA.
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13
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The Role of Rigid Residues in Modulating TEM-1 β-Lactamase Function and Thermostability. Int J Mol Sci 2021; 22:ijms22062895. [PMID: 33809335 PMCID: PMC7999226 DOI: 10.3390/ijms22062895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 01/18/2023] Open
Abstract
The relationship between protein motions (i.e., dynamics) and enzymatic function has begun to be explored in β-lactamases as a way to advance our understanding of these proteins. In a recent study, we analyzed the dynamic profiles of TEM-1 (a ubiquitous class A β-lactamase) and several ancestrally reconstructed homologues. A chief finding of this work was that rigid residues that were allosterically coupled to the active site appeared to have profound effects on enzyme function, even when separated from the active site by many angstroms. In the present work, our aim was to further explore the implications of protein dynamics on β-lactamase function by altering the dynamic profile of TEM-1 using computational protein design methods. The Rosetta software suite was used to mutate amino acids surrounding either rigid residues that are highly coupled to the active site or to flexible residues with no apparent communication with the active site. Experimental characterization of ten designed proteins indicated that alteration of residues surrounding rigid, highly coupled residues, substantially affected both enzymatic activity and stability; in contrast, native-like activities and stabilities were maintained when flexible, uncoupled residues, were targeted. Our results provide additional insight into the structure-function relationship present in the TEM family of β-lactamases. Furthermore, the integration of computational protein design methods with analyses of protein dynamics represents a general approach that could be used to extend our understanding of the relationship between dynamics and function in other enzyme classes.
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Tooke CL, Hinchliffe P, Bonomo RA, Schofield CJ, Mulholland AJ, Spencer J. Natural variants modify Klebsiella pneumoniae carbapenemase (KPC) acyl-enzyme conformational dynamics to extend antibiotic resistance. J Biol Chem 2021; 296:100126. [PMID: 33257320 PMCID: PMC7949053 DOI: 10.1074/jbc.ra120.016461] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/21/2020] [Accepted: 11/30/2020] [Indexed: 12/11/2022] Open
Abstract
Class A serine β-lactamases (SBLs) are key antibiotic resistance determinants in Gram-negative bacteria. SBLs neutralize β-lactams via a hydrolytically labile covalent acyl-enzyme intermediate. Klebsiella pneumoniae carbapenemase (KPC) is a widespread SBL that hydrolyzes carbapenems, the most potent β-lactams; known KPC variants differ in turnover of expanded-spectrum oxyimino-cephalosporins (ESOCs), for example, cefotaxime and ceftazidime. Here, we compare ESOC hydrolysis by the parent enzyme KPC-2 and its clinically observed double variant (P104R/V240G) KPC-4. Kinetic analyses show that KPC-2 hydrolyzes cefotaxime more efficiently than the bulkier ceftazidime, with improved ESOC turnover by KPC-4 resulting from enhanced turnover (kcat), rather than altered KM values. High-resolution crystal structures of ESOC acyl-enzyme complexes with deacylation-deficient (E166Q) KPC-2 and KPC-4 mutants show that ceftazidime acylation causes rearrangement of three loops; the Ω, 240, and 270 loops, which border the active site. However, these rearrangements are less pronounced in the KPC-4 than the KPC-2 ceftazidime acyl-enzyme and are not observed in the KPC-2:cefotaxime acyl-enzyme. Molecular dynamics simulations of KPC:ceftazidime acyl-enyzmes reveal that the deacylation general base E166, located on the Ω loop, adopts two distinct conformations in KPC-2, either pointing "in" or "out" of the active site; with only the "in" form compatible with deacylation. The "out" conformation was not sampled in the KPC-4 acyl-enzyme, indicating that efficient ESOC breakdown is dependent upon the ordering and conformation of the KPC Ω loop. The results explain how point mutations expand the activity spectrum of the clinically important KPC SBLs to include ESOCs through their effects on the conformational dynamics of the acyl-enzyme intermediate.
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Affiliation(s)
- Catherine L Tooke
- School of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom; Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, United Kingdom
| | - Philip Hinchliffe
- School of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - Robert A Bonomo
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA; Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Biochemistry, and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA; CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES) Cleveland, Ohio, USA
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, United Kingdom
| | - James Spencer
- School of Cellular and Molecular Medicine, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom.
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