1
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Chikunova A, Manley MP, Heijjer CN, Drenth CS, Cramer-Blok AJ, Ahmad MUD, Perrakis A, Ubbink M. Conserved proline residues prevent dimerization and aggregation in the β-lactamase BlaC. Protein Sci 2024; 33:e4972. [PMID: 38533527 DOI: 10.1002/pro.4972] [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: 12/08/2023] [Revised: 03/07/2024] [Accepted: 03/11/2024] [Indexed: 03/28/2024]
Abstract
Evolution leads to conservation of amino acid residues in protein families. Conserved proline residues are usually considered to ensure the correct folding and to stabilize the three-dimensional structure. Surprisingly, proline residues that are highly conserved in class A β-lactamases were found to tolerate various substitutions without large losses in enzyme activity. We investigated the roles of three conserved prolines at positions 107, 226, and 258 in the β-lactamase BlaC from Mycobacterium tuberculosis and found that mutations can lead to dimerization of the enzyme and an overall less stable protein that is prone to aggregate over time. For the variant Pro107Thr, the crystal structure shows dimer formation resembling domain swapping. It is concluded that the proline substitutions loosen the structure, enhancing multimerization. Even though the enzyme does not lose its properties without the conserved proline residues, the prolines ensure the long-term structural integrity of the enzyme.
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Affiliation(s)
- A Chikunova
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - M P Manley
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - C N Heijjer
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - C S Drenth
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - A J Cramer-Blok
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
| | - M Ud Din Ahmad
- Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands
- Oncode Institute, Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - A Perrakis
- Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands
- Oncode Institute, Division of Biochemistry, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - M Ubbink
- Leiden Institute of Chemistry, Leiden University, Leiden, The Netherlands
- Department of Infectious Diseases, Imperial College, London, UK
- Zocdoc, New York City, New York, USA
- ZoBio BV, Leiden, The Netherlands
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2
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Amisaki T. Multilevel superposition for deciphering the conformational variability of protein ensembles. Brief Bioinform 2024; 25:bbae137. [PMID: 38557679 PMCID: PMC10983786 DOI: 10.1093/bib/bbae137] [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: 09/26/2023] [Revised: 02/14/2024] [Accepted: 03/10/2024] [Indexed: 04/04/2024] Open
Abstract
The dynamics and variability of protein conformations are directly linked to their functions. Many comparative studies of X-ray protein structures have been conducted to elucidate the relevant conformational changes, dynamics and heterogeneity. The rapid increase in the number of experimentally determined structures has made comparison an effective tool for investigating protein structures. For example, it is now possible to compare structural ensembles formed by enzyme species, variants or the type of ligands bound to them. In this study, the author developed a multilevel model for estimating two covariance matrices that represent inter- and intra-ensemble variability in the Cartesian coordinate space. Principal component analysis using the two estimated covariance matrices identified the inter-/intra-enzyme variabilities, which seemed to be important for the enzyme functions, with the illustrative examples of cytochrome P450 family 2 enzymes and class A $\beta$-lactamases. In P450, in which each enzyme has its own active site of a distinct size, an active-site motion shared universally between the enzymes was captured as the first principal mode of the intra-enzyme covariance matrix. In this case, the method was useful for understanding the conformational variability after adjusting for the differences between enzyme sizes. The developed method is advantageous in small ensemble-size problems and hence promising for use in comparative studies on experimentally determined structures where ensemble sizes are smaller than those generated, for example, by molecular dynamics simulations.
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Affiliation(s)
- Takashi Amisaki
- Department of Biological Regulation, Faculty of Medicine, Tottori University, Yonago, Tottori 683-8503, Japan
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3
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Olehnovics E, Yin J, Pérez A, De Fabritiis G, Bonomo RA, Bhowmik D, Haider S. The Role of Hydrophobic Nodes in the Dynamics of Class A β-Lactamases. Front Microbiol 2021; 12:720991. [PMID: 34621251 PMCID: PMC8490755 DOI: 10.3389/fmicb.2021.720991] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/09/2021] [Indexed: 11/16/2022] Open
Abstract
Class A β-lactamases are known for being able to rapidly gain broad spectrum catalytic efficiency against most β-lactamase inhibitor combinations as a result of elusively minor point mutations. The evolution in class A β-lactamases occurs through optimisation of their dynamic phenotypes at different timescales. At long-timescales, certain conformations are more catalytically permissive than others while at the short timescales, fine-grained optimisation of free energy barriers can improve efficiency in ligand processing by the active site. Free energy barriers, which define all coordinated movements, depend on the flexibility of the secondary structural elements. The most highly conserved residues in class A β-lactamases are hydrophobic nodes that stabilize the core. To assess how the stable hydrophobic core is linked to the structural dynamics of the active site, we carried out adaptively sampled molecular dynamics (MD) simulations in four representative class A β-lactamases (KPC-2, SME-1, TEM-1, and SHV-1). Using Markov State Models (MSM) and unsupervised deep learning, we show that the dynamics of the hydrophobic nodes is used as a metastable relay of kinetic information within the core and is coupled with the catalytically permissive conformation of the active site environment. Our results collectively demonstrate that the class A enzymes described here, share several important dynamic similarities and the hydrophobic nodes comprise of an informative set of dynamic variables in representative class A β-lactamases.
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Affiliation(s)
- Edgar Olehnovics
- Pharmaceutical and Biological Chemistry, University College London School of Pharmacy, London, United Kingdom
| | - Junqi Yin
- Oak Ridge National Laboratory, National Center for Computational Sciences, Oak Ridge, TN, United States
| | - Adrià Pérez
- Computational Science Laboratory, Barcelona Biomedical Research Park, Universitat Pompeu Fabra, Barcelona, Spain
| | - Gianni De Fabritiis
- Computational Science Laboratory, Barcelona Biomedical Research Park, Universitat Pompeu Fabra, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Robert A. Bonomo
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH, United States
- Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, United States
- Department of Proteomics and Bioinformatics, Case Western Reserve University, Cleveland, OH, United States
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, OH, United States
- Veterans Affairs Northeast Ohio Healthcare System, Research Service, Cleveland, OH, United States
| | - Debsindhu Bhowmik
- Computer Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Shozeb Haider
- Pharmaceutical and Biological Chemistry, University College London School of Pharmacy, London, United Kingdom
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4
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Galdadas I, Qu S, Oliveira ASF, Olehnovics E, Mack AR, Mojica MF, Agarwal PK, Tooke CL, Gervasio FL, Spencer J, Bonomo RA, Mulholland AJ, Haider S. Allosteric communication in class A β-lactamases occurs via cooperative coupling of loop dynamics. eLife 2021; 10:e66567. [PMID: 33755013 PMCID: PMC8060031 DOI: 10.7554/elife.66567] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/19/2021] [Indexed: 12/16/2022] Open
Abstract
Understanding allostery in enzymes and tools to identify it offer promising alternative strategies to inhibitor development. Through a combination of equilibrium and nonequilibrium molecular dynamics simulations, we identify allosteric effects and communication pathways in two prototypical class A β-lactamases, TEM-1 and KPC-2, which are important determinants of antibiotic resistance. The nonequilibrium simulations reveal pathways of communication operating over distances of 30 Å or more. Propagation of the signal occurs through cooperative coupling of loop dynamics. Notably, 50% or more of clinically relevant amino acid substitutions map onto the identified signal transduction pathways. This suggests that clinically important variation may affect, or be driven by, differences in allosteric behavior, providing a mechanism by which amino acid substitutions may affect the relationship between spectrum of activity, catalytic turnover, and potential allosteric behavior in this clinically important enzyme family. Simulations of the type presented here will help in identifying and analyzing such differences.
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Affiliation(s)
- Ioannis Galdadas
- University College London, Department of ChemistryLondonUnited Kingdom
| | - Shen Qu
- University College London School of Pharmacy, Pharmaceutical and Biological ChemistryLondonUnited Kingdom
| | - Ana Sofia F Oliveira
- University of Bristol, Centre for Computational Chemistry, School of ChemistryBristolUnited Kingdom
| | - Edgar Olehnovics
- University College London School of Pharmacy, Pharmaceutical and Biological ChemistryLondonUnited Kingdom
| | - Andrew R Mack
- Veterans Affairs Northeast Ohio Healthcare System, Research ServiceClevelandUnited States
- Case Western Reserve University, Department of Molecular Biology and MicrobiologyClevelandUnited States
| | - Maria F Mojica
- Veterans Affairs Northeast Ohio Healthcare System, Research ServiceClevelandUnited States
- Case Western Reserve University, Department of Infectious Diseases, School of MedicineClevelandUnited States
| | - Pratul K Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State UniversityStillwaterUnited States
| | - Catherine L Tooke
- University of Bristol, School of Cellular and Molecular MedicineBristolUnited Kingdom
| | - Francesco Luigi Gervasio
- University College London, Department of ChemistryLondonUnited Kingdom
- University College London, Institute of Structural and Molecular BiologyLondonUnited Kingdom
- University of Geneva, Pharmaceutical SciencesGenevaSwitzerland
| | - James Spencer
- University of Bristol, School of Cellular and Molecular MedicineBristolUnited Kingdom
| | - Robert A Bonomo
- Veterans Affairs Northeast Ohio Healthcare System, Research ServiceClevelandUnited States
- Case Western Reserve University, Department of Molecular Biology and MicrobiologyClevelandUnited States
- Case Western Reserve University, Department of Infectious Diseases, School of MedicineClevelandUnited States
- Case Western Reserve University, Department of BiochemistryClevelandUnited States
- Case Western Reserve University, Department of PharmacologyClevelandUnited States
- Case Western Reserve University, Department of Proteomics and BioinformaticsClevelandUnited States
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES)ClevelandUnited States
| | - Adrian J Mulholland
- University of Bristol, Centre for Computational Chemistry, School of ChemistryBristolUnited Kingdom
| | - Shozeb Haider
- University College London School of Pharmacy, Pharmaceutical and Biological ChemistryLondonUnited Kingdom
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5
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Can We Exploit β-Lactamases Intrinsic Dynamics for Designing More Effective Inhibitors? Antibiotics (Basel) 2020; 9:antibiotics9110833. [PMID: 33233339 PMCID: PMC7700307 DOI: 10.3390/antibiotics9110833] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 12/17/2022] Open
Abstract
β-lactamases (BLs) represent the most frequent cause of antimicrobial resistance in Gram-negative bacteria. Despite the continuous efforts in the development of BL inhibitors (BLIs), new BLs able to hydrolyze the last developed antibiotics rapidly emerge. Moreover, the insurgence rate of effective mutations is far higher than the release of BLIs able to counteract them. This results in a shortage of antibiotics that is menacing the effective treating of infectious diseases. The situation is made even worse by the co-expression in bacteria of BLs with different mechanisms and hydrolysis spectra, and by the lack of inhibitors able to hit them all. Differently from other targets, BL flexibility has not been deeply exploited for drug design, possibly because of the small protein size, for their apparent rigidity and their high fold conservation. In this mini-review, we discuss the evidence for BL binding site dynamics being crucial for catalytic efficiency, mutation effect, and for the design of new inhibitors. Then, we report on identified allosteric sites in BLs and on possible allosteric inhibitors, as a strategy to overcome the frequent occurrence of mutations in BLs and the difficulty of competing efficaciously with substrates. Nevertheless, allosteric inhibitors could work synergistically with traditional inhibitors, increasing the chances of restoring bacterial susceptibility towards available antibiotics.
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6
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Yadav TC, Agarwal V, Srivastava AK, Raghuwanshi N, Varadwaj P, Prasad R, Pruthi V. Insight into Structure-Function Relationships of β-Lactamase and BLIPs Interface Plasticity using Protein-Protein Interactions. Curr Pharm Des 2020; 25:3378-3389. [PMID: 31544712 DOI: 10.2174/1381612825666190911154650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/05/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Mostly BLIPs are identified in soil bacteria Streptomyces and originally isolated from Streptomyces clavuligerus and can be utilized as a model system for biophysical, structural, mutagenic and computational studies. BLIP possess homology with two proteins viz., BLIP-I (Streptomyces exofoliatus) and BLP (beta-lactamase inhibitory protein like protein from S. clavuligerus). BLIP consists of 165 amino acid, possessing two homologues domains comprising helix-loop-helix motif packed against four stranded beta-sheet resulting into solvent exposed concave surface with extended four stranded beta-sheet. BLIP-I is a 157 amino acid long protein obtained from S. exofoliatus having 37% sequence identity to BLIP and inhibits beta-lactamase. METHODS This review is intended to briefly illustrate the beta-lactamase inhibitory activity of BLIP via proteinprotein interaction and aims to open up a new avenue to combat antimicrobial resistance using peptide based inhibition. RESULTS D49A mutation in BLIP-I results in a decrease in affinity for TEM-1 from 0.5 nM to 10 nM (Ki). It is capable of inhibiting TEM-1 and bactopenemase and differs from BLIP only in modulating cell wall synthesis enzyme. Whereas, BLP is a 154 amino acid long protein isolated from S. clavuligerus via DNA sequencing analysis of Cephamycin-Clavulanate gene bunch. It shares 32% sequence similarity with BLIP and 42% with BLIP-I. Its biological function is unclear and lacks beta-lactamase inhibitory activity. CONCLUSION Protein-protein interactions mediate a significant role in regulation and modulation of cellular developments and processes. Specific biological markers and geometric characteristics are manifested by active site binding clefts of protein surfaces which determines the specificity and affinity for their targets. TEM1.BLIP is a classical model to study protein-protein interaction. β-Lactamase inhibitory proteins (BLIPs) interacts and inhibits various β-lactamases with extensive range of affinities.
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Affiliation(s)
- Tara C Yadav
- Department of Biotechnology, Indian Institute of Technology, Roorkee-247667, Uttarakhand, India
| | - Vidhu Agarwal
- Department of Bioinformatics, Indian Institute of Information Technology, Allahabad 211015, India
| | - Amit K Srivastava
- Department of Biotechnology, Indian Institute of Technology, Roorkee-247667, Uttarakhand, India
| | - Navdeep Raghuwanshi
- Vaccine Formulation & Research Center, Gennova (Emcure) Biopharmaceuticals Limited, Pune - 11057, Maharashtra, India
| | - Pritish Varadwaj
- Department of Bioinformatics, Indian Institute of Information Technology, Allahabad 211015, India
| | - Ramasare Prasad
- Department of Biotechnology, Indian Institute of Technology, Roorkee-247667, Uttarakhand, India
| | - Vikas Pruthi
- Department of Biotechnology, Indian Institute of Technology, Roorkee-247667, Uttarakhand, India
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7
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The Role of the Ω-Loop in Regulation of the Catalytic Activity of TEM-Type β-Lactamases. Biomolecules 2019; 9:biom9120854. [PMID: 31835662 PMCID: PMC6995641 DOI: 10.3390/biom9120854] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 11/23/2022] Open
Abstract
Bacterial resistance to β-lactams, the most commonly used class of antibiotics, poses a global challenge. This resistance is caused by the production of bacterial enzymes that are termed β-lactamases (βLs). The evolution of serine-class A β-lactamases from penicillin-binding proteins (PBPs) is related to the formation of the Ω-loop at the entrance to the enzyme’s active site. In this loop, the Glu166 residue plays a key role in the two-step catalytic cycle of hydrolysis. This residue in TEM–type β-lactamases, together with Asn170, is involved in the formation of a hydrogen bonding network with a water molecule, leading to the deacylation of the acyl–enzyme complex and the hydrolysis of the β-lactam ring of the antibiotic. The activity exhibited by the Ω-loop is attributed to the positioning of its N-terminal residues near the catalytically important residues of the active site. The structure of the Ω-loop of TEM-type β-lactamases is characterized by low mutability, a stable topology, and structural flexibility. All of the revealed features of the Ω-loop, as well as the mechanisms related to its involvement in catalysis, make it a potential target for novel allosteric inhibitors of β-lactamases.
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8
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Wang F, Shen L, Zhou H, Wang S, Wang X, Tao P. Machine Learning Classification Model for Functional Binding Modes of TEM-1 β-Lactamase. Front Mol Biosci 2019; 6:47. [PMID: 31355207 PMCID: PMC6629954 DOI: 10.3389/fmolb.2019.00047] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 06/11/2019] [Indexed: 11/13/2022] Open
Abstract
TEM family of enzymes is one of the most commonly encountered β-lactamases groups with different catalytic capabilities against various antibiotics. Despite the studies investigating the catalytic mechanism of TEM β-lactamases, the binding modes of these enzymes against ligands in different functional catalytic states have been largely overlooked. But the binding modes may play a critical role in the function and even the evolution of these proteins. In this work, a newly developed machine learning analysis approach to the recognition of protein dynamics states was applied to compare the binding modes of TEM-1 β-lactamase with regard to penicillin in different catalytic states. While conventional analysis methods, including principal components analysis (PCA), could not differentiate TEM-1 in different binding modes, the application of a machine learning method led to excellent classification models differentiating these states. It was also revealed that both reactant/product states and apo/product states are more differentiable than the apo/reactant states. The feature importance generated by the training procedure of the machine learning model was utilized to evaluate the contribution from residues at active sites and in different secondary structures. Key active site residues, Ser70 and Ser130, play a critical role in differentiating reactant/product states, while other active site residues are more important for differentiating apo/product states. Overall, this study provides new insights into the different dynamical function states of TEM-1 and may open a new venue for β-lactamases functional and evolutional studies in general.
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Affiliation(s)
- Feng Wang
- Department of Chemistry, Center for Scientific Computation, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX, United States
| | - Li Shen
- Department of Chemistry, Center for Scientific Computation, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX, United States
| | - Hongyu Zhou
- Department of Chemistry, Center for Scientific Computation, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX, United States
| | - Shouyi Wang
- Department of Industrial, Manufacturing, and Systems Engineering, University of Texas at Arlington, Arlington, TX, United States
| | - Xinlei Wang
- Department of Statistical Science, Southern Methodist University, Dallas, TX, United States
| | - Peng Tao
- Department of Chemistry, Center for Scientific Computation, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX, United States
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9
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Defining the architecture of KPC-2 Carbapenemase: identifying allosteric networks to fight antibiotics resistance. Sci Rep 2018; 8:12916. [PMID: 30150677 PMCID: PMC6110804 DOI: 10.1038/s41598-018-31176-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 08/13/2018] [Indexed: 11/08/2022] Open
Abstract
The rise of multi-drug resistance in bacterial pathogens is one of the grand challenges facing medical science. A major concern is the speed of development of β-lactamase-mediated resistance in Gram-negative species, thus putting at risk the efficacy of the most recently approved antibiotics and inhibitors, including carbapenems and avibactam, respectively. New strategies to overcome resistance are urgently required, which will ultimately be facilitated by a deeper understanding of the mechanisms that regulate the function of β-lactamases such as the Klebsiella Pneumoniae carbapenemases (KPCs). Using enhanced sampling computational methods together with site-directed mutagenesis, we report the identification of two “hydrophobic networks” in the KPC-2 enzyme, the integrity of which has been found to be essential for protein stability and corresponding resistance. Present throughout the structure, these networks are responsible for the structural integrity and allosteric signaling. Disruption of the networks leads to a loss of the KPC-2 mediated resistance phenotype, resulting in restored susceptibility to different classes of β-lactam antibiotics including carbapenems and cephalosporins. The ”hydrophobic networks” were found to be highly conserved among class-A β-lactamases, which implies their suitability for exploitation as a potential target for therapeutic intervention.
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10
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Tackling the Antibiotic Resistance Caused by Class A β-Lactamases through the Use of β-Lactamase Inhibitory Protein. Int J Mol Sci 2018; 19:ijms19082222. [PMID: 30061509 PMCID: PMC6121496 DOI: 10.3390/ijms19082222] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 07/23/2018] [Accepted: 07/25/2018] [Indexed: 12/27/2022] Open
Abstract
β-Lactams are the most widely used and effective antibiotics for the treatment of infectious diseases. Unfortunately, bacteria have developed several mechanisms to combat these therapeutic agents. One of the major resistance mechanisms involves the production of β-lactamase that hydrolyzes the β-lactam ring thereby inactivating the drug. To overcome this threat, the small molecule β-lactamase inhibitors (e.g., clavulanic acid, sulbactam and tazobactam) have been used in combination with β-lactams for treatment. However, the bacterial resistance to this kind of combination therapy has evolved recently. Therefore, multiple attempts have been made to discover and develop novel broad-spectrum β-lactamase inhibitors that sufficiently work against β-lactamase producing bacteria. β-lactamase inhibitory proteins (BLIPs) (e.g., BLIP, BLIP-I and BLIP-II) are potential inhibitors that have been found from soil bacterium Streptomyces spp. BLIPs bind and inhibit a wide range of class A β-lactamases from a diverse set of Gram-positive and Gram-negative bacteria, including TEM-1, PC1, SME-1, SHV-1 and KPC-2. To the best of our knowledge, this article represents the first systematic review on β-lactamase inhibitors with a particular focus on BLIPs and their inherent properties that favorably position them as a source of biologically-inspired drugs to combat antimicrobial resistance. Furthermore, an extensive compilation of binding data from β-lactamase–BLIP interaction studies is presented herein. Such information help to provide key insights into the origin of interaction that may be useful for rationally guiding future drug design efforts.
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11
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Targeting a hidden site on class A beta-lactamases. J Mol Graph Model 2018; 84:125-133. [PMID: 29960255 DOI: 10.1016/j.jmgm.2018.06.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 06/05/2018] [Accepted: 06/07/2018] [Indexed: 11/22/2022]
Abstract
Increasing resistance against available orthosteric beta-lactamase inhibitors necessitates the search for novel and powerful inhibitor molecules. In this respect, allosteric inhibitors serve as attractive alternatives. Here, we examine the structural basis of inhibition in a hidden, druggable pocket in TEM-1 beta-lactamase. Based on crystallographic evidence that 6-cyclohexyl-1-hexyl-β-D-maltoside (CYMAL-6) binds to this site, first we determined the kinetic mechanism of inhibition by CYMAL-6. Activity measurements with CYMAL-6 showed that it competitively inhibits the wild type enzyme. Interestingly, it exhibits a steep dose-response curve with an IC50 of 100 μM. The IC50 value changes neither with different enzyme concentration nor with incubation of the enzyme with the inhibitor, showing that inhibition is not aggregation-based. The presence of the same concentrations of CYMAL-6 does not influence the activity of lactate dehydrogenase, further confirming the specificity of CYMAL-6 for TEM-1 beta-lactamase. Then, we identified compounds with high affinity to this allosteric site by virtual screening using Glide and Schrödinger Suite. Virtual screening performed with 500,000 drug like compounds from the ZINC database showed that top scoring compounds interact with the hydrophobic pocket that forms between H10 and H11 helices and with the catalytically important Arg244 residue through pi-cation interactions. Discovery of novel chemical scaffolds that target this allosteric site will pave the way for a new avenue in the design of new antimicrobials.
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12
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Avci FG, Altinisik FE, Vardar Ulu D, Ozkirimli Olmez E, Sariyar Akbulut B. An evolutionarily conserved allosteric site modulates beta-lactamase activity. J Enzyme Inhib Med Chem 2016; 31:33-40. [PMID: 27353461 DOI: 10.1080/14756366.2016.1201813] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Declining efficiency of antibiotic-inhibitor combinatorial therapies in treating beta-lactamase mediated resistance necessitates novel inhibitor development. Allosteric inhibition offers an alternative to conventional drugs that target the conserved active site. Here, we show that the evolutionarily conserved PWP triad located at the N-terminus of the H10 helix directly interacts with the allosteric site in TEM-1 beta-lactamase and regulates its activity. While point mutations in the PWP triad preserve the overall secondary structures around the allosteric site, they result in a more open and dynamic global structure with decreased chemical stability and increased aggregation propensity. These mutant enzymes with a less compact hydrophobic core around the allosteric site displayed significant activity loss. Detailed sequence and structure conservation analyses revealed that the PWP triad is an evolutionarily conserved motif unique to class A beta-lactamases aligning its allosteric site and hence is an effective potential target for enzyme regulation and selective drug design.
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Affiliation(s)
- Fatma Gizem Avci
- a Department of Bioengineering , Marmara University , İstanbul , Turkey
| | | | - Didem Vardar Ulu
- b Department of Chemistry , Boston University , Boston , MA , USA , and
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