1
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Lorentzen ØM, Haukefer ASB, Johnsen PJ, Frøhlich C. The Biofilm Lifestyle Shapes the Evolution of β-Lactamases. Genome Biol Evol 2024; 16:evae030. [PMID: 38366392 PMCID: PMC10917518 DOI: 10.1093/gbe/evae030] [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: 11/06/2023] [Revised: 02/02/2024] [Accepted: 02/08/2024] [Indexed: 02/18/2024] Open
Abstract
The evolutionary relationship between the biofilm lifestyle and antibiotic resistance enzymes remains a subject of limited understanding. Here, we investigate how β-lactamases affect biofilm formation in Vibrio cholerae and how selection for a biofilm lifestyle impacts the evolution of these enzymes. Genetically diverse β-lactamases expressed in V. cholerae displayed a strong inhibitory effect on biofilm production. To understand how natural evolution affects this antagonistic pleiotropy, we randomly mutagenized a β-lactamase and selected for elevated biofilm formation. Our results revealed that biofilm evolution selects for β-lactamase variants able to hydrolyze β-lactams without inhibiting biofilms. Mutational analysis of evolved variants demonstrated that restoration of biofilm development was achieved either independently of enzymatic function or by actively leveraging enzymatic activity. Taken together, the biofilm lifestyle can impose a profound selective pressure on antimicrobial resistance enzymes. Shedding light on such evolutionary interplays is of importance to understand the factors driving antimicrobial resistance.
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Affiliation(s)
- Øyvind M Lorentzen
- Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
| | | | - Pål J Johnsen
- Department of Pharmacy, UiT The Arctic University of Norway, Tromsø, Norway
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2
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Yehorova D, Crean RM, Kasson PM, Kamerlin SCL. Key interaction networks: Identifying evolutionarily conserved non-covalent interaction networks across protein families. Protein Sci 2024; 33:e4911. [PMID: 38358258 PMCID: PMC10868456 DOI: 10.1002/pro.4911] [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: 11/03/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/16/2024]
Abstract
Protein structure (and thus function) is dictated by non-covalent interaction networks. These can be highly evolutionarily conserved across protein families, the members of which can diverge in sequence and evolutionary history. Here we present KIN, a tool to identify and analyze conserved non-covalent interaction networks across evolutionarily related groups of proteins. KIN is available for download under a GNU General Public License, version 2, from https://www.github.com/kamerlinlab/KIN. KIN can operate on experimentally determined structures, predicted structures, or molecular dynamics trajectories, providing insight into both conserved and missing interactions across evolutionarily related proteins. This provides useful insight both into protein evolution, as well as a tool that can be exploited for protein engineering efforts. As a showcase system, we demonstrate applications of this tool to understanding the evolutionary-relevant conserved interaction networks across the class A β-lactamases.
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Affiliation(s)
- Dariia Yehorova
- School of Chemistry and Biochemistry, Georgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Rory M. Crean
- Department of Chemistry—BMCUppsala UniversityUppsalaSweden
| | - Peter M. Kasson
- Department of Molecular PhysiologyUniversity of VirginiaCharlottesvilleVirginiaUSA
- Department Biomedical EngineeringUniversity of VirginiaCharlottesvilleVirginiaUSA
- Department of Cell and Molecular BiologyUppsala UniversityUppsalaSweden
| | - Shina C. L. Kamerlin
- School of Chemistry and Biochemistry, Georgia Institute of TechnologyAtlantaGeorgiaUSA
- Department of Chemistry—BMCUppsala UniversityUppsalaSweden
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3
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Nafaee ZH, Egyed V, Jancsó A, Tóth A, Gerami AM, Dang TT, Heiniger‐Schell J, Hemmingsen L, Hunyadi‐Gulyás É, Peintler G, Gyurcsik B. Revisiting the hydrolysis of ampicillin catalyzed by Temoneira-1 β-lactamase, and the effect of Ni(II), Cd(II) and Hg(II). Protein Sci 2023; 32:e4809. [PMID: 37853808 PMCID: PMC10661098 DOI: 10.1002/pro.4809] [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: 04/21/2023] [Revised: 09/18/2023] [Accepted: 10/15/2023] [Indexed: 10/20/2023]
Abstract
β-Lactamases grant resistance to bacteria against β-lactam antibiotics. The active center of TEM-1 β-lactamase accommodates a Ser-Xaa-Xaa-Lys motif. TEM-1 β-lactamase is not a metalloenzyme but it possesses several putative metal ion binding sites. The sites composed of His residue pairs chelate borderline transition metal ions such as Ni(II). In addition, there are many sulfur-containing donor groups that can coordinate soft metal ions such as Hg(II). Cd(II) may bind to both types of the above listed donor groups. No significant change was observed in the circular dichroism spectra of TEM-1 β-lactamase on increasing the metal ion content of the samples, with the exception of Hg(II) inducing a small change in the secondary structure of the protein. A weak nonspecific binding of Hg(II) was proven by mass spectrometry and 119m Hg perturbed angular correlation spectroscopy. The hydrolytic process of ampicillin catalyzed by TEM-1 β-lactamase was described by the kinetic analysis of the set of full catalytic progress curves, where the slow, yet observable conversion of the primary reaction product into a second one, identified as ampilloic acid by mass spectrometry, needed also to be considered in the applied model. Ni(II) and Cd(II) slightly promoted the catalytic activity of the enzyme while Hg(II) exerted a noticeable inhibitory effect. Hg(II) and Ni(II), applied at 10 μM concentration, inhibited the growth of E. coli BL21(DE3) in M9 minimal medium in the absence of ampicillin, but addition of the antibiotic could neutralize this toxic effect by complexing the metal ions.
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Affiliation(s)
- Zeyad H. Nafaee
- Department of Molecular and Analytical ChemistryUniversity of SzegedSzegedHungary
- College of PharmacyUniversity of BabylonBabelIraq
| | - Viktória Egyed
- Department of Molecular and Analytical ChemistryUniversity of SzegedSzegedHungary
| | - Attila Jancsó
- Department of Molecular and Analytical ChemistryUniversity of SzegedSzegedHungary
| | - Annamária Tóth
- Department of Molecular and Analytical ChemistryUniversity of SzegedSzegedHungary
| | - Adeleh Mokhles Gerami
- School of Particles and AcceleratorsInstitute for Research in Fundamental Sciences (IPM)TehranIran
- European Organization for Nuclear Research (CERN)GenevaSwitzerland
| | - Thanh Thien Dang
- Institute for Materials Science and Center for Nanointegration Duisburg‐Essen (CENIDE)University of Duisburg‐EssenEssenGermany
| | - Juliana Heiniger‐Schell
- European Organization for Nuclear Research (CERN)GenevaSwitzerland
- Institute for Materials Science and Center for Nanointegration Duisburg‐Essen (CENIDE)University of Duisburg‐EssenEssenGermany
| | - Lars Hemmingsen
- Department of ChemistryUniversity of CopenhagenCopenhagenDenmark
| | - Éva Hunyadi‐Gulyás
- Laboratory of Proteomics Research, Biological Research CentreHungarian Research Network (HUN‐REN)SzegedHungary
| | - Gábor Peintler
- Department of Physical Chemistry and Material SciencesUniversity of SzegedSzegedHungary
| | - Béla Gyurcsik
- Department of Molecular and Analytical ChemistryUniversity of SzegedSzegedHungary
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4
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Abioye OE, Nontongana N, Osunla CA, Okoh AI. Antibiotic resistance and virulence genes profiling of Vibrio cholerae and Vibrio mimicus isolates from some seafood collected at the aquatic environment and wet markets in Eastern Cape Province, South Africa. PLoS One 2023; 18:e0290356. [PMID: 37616193 PMCID: PMC10449182 DOI: 10.1371/journal.pone.0290356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 08/04/2023] [Indexed: 08/26/2023] Open
Abstract
The current study determines the density of Vibrio spp. and isolates V. cholerae and Vibrio mimicus from fish-anatomical-sites, prawn, crab and mussel samples recovered from fish markets, freshwater and brackish water. Virulence and antibiotic resistance profiling of isolates were carried out using standard molecular and microbiology techniques. Vibrio spp. was detected in more than 90% of samples [134/144] and its density was significantly more in fish than in other samples. Vibrio. cholerae and V. mimicus were isolated in at least one sample of each sample type with higher isolation frequency in fish samples. All the V. cholerae isolates belong to non-O1/non-O139 serogroup. One or more V. cholerae isolates exhibited intermediate or resistance against each of the eighteen panels of antibiotics used but 100% of the V. mimicus were susceptible to amikacin, gentamycin and chloramphenicol. Vibrio cholerae exhibited relatively high resistance against polymyxin, ampicillin and amoxicillin/clavulanate while V. mimicus isolates exhibited relatively high resistance against nitrofurantoin, ampicillin and polymixin. The multiple-antibiotic-resistance-index [MARI] for isolates ranges between 0 and 0.67 and 48% of the isolates have MARI that is >0.2 while 55% of the isolates exhibit MultiDrug Resistance Phenotypes. The percentage detection of acc, ant, drf18, sul1, mcr-1, blasvh, blaoxa, blatem, blaoxa48, gyrA, gyrB and parC resistance-associated genes were 2%, 9%, 14%, 7%, 2%, 25%, 7%, 2%, 2%, 32%, 25% and 27% respectively while that for virulence-associated genes in increasing other was ace [2%], tcp [11%], vpi [16%], ompU [34%], toxR [43%], rtxC [70%], rtxA [73%] and hyla [77%]. The study confirmed the potential of environmental non-O1/non-O139 V. cholerae and V. mimicus to cause cholera-like infection and other vibriosis which could be difficult to manage with commonly recommended antibiotics. Thus, regular monitoring of the environment to create necessary awareness for this kind of pathogens is important in the interest of public health.
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Affiliation(s)
| | - Nolonwabo Nontongana
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, South Africa
| | - Charles A. Osunla
- Department of Microbiology, Adekunle Ajasin University, Akungba Akoko, Nigeria
| | - Anthony I. Okoh
- SAMRC Microbial Water Quality Monitoring Centre, University of Fort Hare, Alice, South Africa
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5
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Judge A, Hu L, Sankaran B, Van Riper J, Venkataram Prasad BV, Palzkill T. Mapping the determinants of catalysis and substrate specificity of the antibiotic resistance enzyme CTX-M β-lactamase. Commun Biol 2023; 6:35. [PMID: 36635385 PMCID: PMC9837174 DOI: 10.1038/s42003-023-04422-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 01/04/2023] [Indexed: 01/14/2023] Open
Abstract
CTX-M β-lactamases are prevalent antibiotic resistance enzymes and are notable for their ability to rapidly hydrolyze the extended-spectrum cephalosporin, cefotaxime. We hypothesized that the active site sequence requirements of CTX-M-mediated hydrolysis differ between classes of β-lactam antibiotics. Accordingly, we use codon randomization, antibiotic selection, and deep sequencing to determine the CTX-M active-site residues required for hydrolysis of cefotaxime and the penicillin, ampicillin. The study reveals positions required for hydrolysis of all β-lactams, as well as residues controlling substrate specificity. Further, CTX-M enzymes poorly hydrolyze the extended-spectrum cephalosporin, ceftazidime. We further show that the sequence requirements for ceftazidime hydrolysis follow those of cefotaxime, with the exception that key active-site omega loop residues are not required, and may be detrimental, for ceftazidime hydrolysis. These results provide insights into cephalosporin hydrolysis and demonstrate that changes to the active-site omega loop are likely required for the evolution of CTX-M-mediated ceftazidime resistance.
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Affiliation(s)
- Allison Judge
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Liya Hu
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Banumathi Sankaran
- Department of Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Justin Van Riper
- Graduate Program in Chemical, Physical, and Structural Biology, Baylor College of Medicine, Houston, TX, USA
| | - B V Venkataram Prasad
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Timothy Palzkill
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA.
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, TX, USA.
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6
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Nervig C, Hatch ST, Owen SC. Complementation Dependent Enzyme Prodrug Therapy Enables Targeted Activation of Prodrug on HER2-Positive Cancer Cells. ACS Med Chem Lett 2022; 13:1769-1775. [PMID: 36385932 PMCID: PMC9661694 DOI: 10.1021/acsmedchemlett.2c00394] [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: 08/22/2022] [Accepted: 10/24/2022] [Indexed: 11/28/2022] Open
Abstract
Antibodies have been explored for decades for the delivery of small molecule cytotoxins directly to diseased cells. In antibody-directed enzyme prodrug therapy (ADEPT), antibodies are armed with enzymes that activate nontoxic prodrugs at tumor sites. However, this strategy failed clinically due to off-target toxicity associated with the enzyme prematurely activating prodrug systemically. We describe here the design of an antibody-fragment split enzyme platform that regains activity after binding to HER2, allowing for site-specific activation of a small molecule prodrug. We evaluated a library of fusion constructs for efficient targeting and complementation to identify the most promising split enzyme pair. The optimal pair was screened for substrate specificity among chromogenic, fluorogenic, and prodrug substrates. Evaluation of this system on HER2-positive cells revealed 7-fold higher toxicity of the activated prodrug over prodrug treatment alone. Demonstrating the potential of this strategy against a known clinical target provides the basis for a unique therapeutic platform in oncology.
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Affiliation(s)
- Christine
S. Nervig
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Samuel T. Hatch
- Department
of Molecular Pharmaceutics, University of
Utah, Salt Lake City, Utah 84112, United
States
| | - Shawn C. Owen
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Department
of Molecular Pharmaceutics, University of
Utah, Salt Lake City, Utah 84112, United
States
- Department
of Biomedical Engineering, University of
Utah, Salt Lake City, Utah 84112, United
States
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7
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Klebsiella pneumoniae Carbapenemase Variants Resistant to Ceftazidime-Avibactam: an Evolutionary Overview. Antimicrob Agents Chemother 2022; 66:e0044722. [PMID: 35980232 PMCID: PMC9487638 DOI: 10.1128/aac.00447-22] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
First variants of the Klebsiella pneumoniae carbapenemase (KPC), KPC-2 and KPC-3, have encountered a worldwide success, particularly in K. pneumoniae isolates. These beta-lactamases conferred resistance to most beta-lactams including carbapenems but remained susceptible to new beta-lactam/beta-lactamase inhibitors, such as ceftazidime-avibactam. After the marketing of ceftazidime-avibactam, numerous variants of KPC resistant to this association have been described among isolates recovered from clinical samples or derived from experimental studies. In KPC variants resistant to ceftazidime-avibactam, point mutations, insertions and/or deletions have been described in various hot spots. Deciphering the impact of these mutations is crucial, not only from a therapeutic point of view, but also to follow the evolution in time and space of KPC variants resistant to ceftazidime-avibactam. In this review, we describe the mutational landscape of the KPC beta-lactamase toward ceftazidime-avibactam resistance based on a multidisciplinary approach including epidemiology, microbiology, enzymology, and thermodynamics. We show that resistance is associated with three hot spots, with a high representation of insertions and deletions compared with other class A beta-lactamases. Moreover, extension of resistance to ceftazidime-avibactam is associated with a trade-off in the resistance to other beta-lactams and a decrease in enzyme stability. Nevertheless, the high natural stability of KPC could underlay the propensity of this enzyme to acquire in vivo mutations conferring resistance to ceftazidime-avibactam (CAZavi), particularly via insertions and deletions.
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8
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Excreted Antibiotics May Be Key to Emergence of Increasingly Efficient Antibiotic Resistance in Food Animal Production. Appl Environ Microbiol 2022; 88:e0079122. [PMID: 35867586 PMCID: PMC9361830 DOI: 10.1128/aem.00791-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
At a time when antibiotic resistance is seemingly ubiquitous worldwide, understanding the mechanisms responsible for successful emergence of new resistance genes may provide insights into the persistence and pathways of dissemination for antibiotic-resistant organisms in general. For example, Escherichia coli strains harboring a class A β-lactamase-encoding gene (blaCTX-M-15) appear to be displacing strains that harbor a class C β-lactamase gene (blaCMY-2) in Washington State dairy cattle. We cloned these genes with native promoters into low-copy-number plasmids that were then transformed into isogenic strains of E. coli, and growth curves were generated for two commonly administered antibiotics (ampicillin and ceftiofur). Both strains met the definition of resistance for ampicillin (≥32 μg/mL) and ceftiofur (≥16 μg/mL). Growth of the CMY-2-producing strain was compromised at 1,000 μg/mL ampicillin, whereas the CTX-M-15-producing strain was not inhibited in the presence of 3,000 μg/mL ampicillin or with most concentrations of ceftiofur, although there were mixed outcomes with ceftiofur metabolites. Consequently, in the absence of competing genes, E. coli harboring either gene would experience a selective advantage if exposed to these antibiotics. Successful emergence of CTX-M-15-producing strains where CMY-2-producing strains are already established, however, requires high concentrations of antibiotics that can only be found in the urine of treated animals (e.g., >2,000 μg/mL for ampicillin, based on literature). This ex vivo selection pressure may be important for the emergence of new and more efficient antibiotic resistance genes and likely for persistence of antibiotic-resistant bacteria in food animal populations. IMPORTANCE We studied the relative fitness benefits of a cephalosporin resistance enzyme (CTX-M-15) that is displacing a similar enzyme (CMY-2), which is extant in E. coli from dairy cattle in Washington State. In vitro experiments demonstrated that CTX-M-15 provides a significant fitness advantage, but only in the presence of very high concentrations of antibiotic that are only found when the antibiotic ampicillin, and to a lesser extent ceftiofur, is excreted in urine from treated animals. As such, the increasing prevalence of bacteria with blaCTX-M-15 is likely occurring ex vivo. Interventions should focus on controlling waste from treated animals and, when possible, selecting antibiotics that are less likely to impact the proximal environment of treated animals.
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9
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Grigorenko VG, Petrova TE, Carolan C, Rubtsova MY, Uporov IV, Pereira J, Chojnowski G, Samygina VR, Lamzin VS, Egorov AM. Crystal structures of the molecular class A β-lactamase TEM-171 and its complexes with tazobactam. Acta Crystallogr D Struct Biol 2022; 78:825-834. [DOI: 10.1107/s2059798322004879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 05/06/2022] [Indexed: 11/10/2022] Open
Abstract
The resistance of bacteria to β-lactam antibiotics is primarily caused by the production of β-lactamases. Here, novel crystal structures of the native β-lactamase TEM-171 and two complexes with the widely used inhibitor tazobactam are presented, alongside complementary data from UV spectroscopy and fluorescence quenching. The six chemically identical β-lactamase molecules in the crystallographic asymmetric unit displayed different degrees of disorder. The tazobactam intermediate was covalently bound to the catalytic Ser70 in the trans-enamine configuration. While the conformation of tazobactam in the first complex resembled that in published β-lactamase–tazobactam structures, in the second complex, which was obtained after longer soaking of the native crystals in the inhibitor solution, a new and previously unreported tazobactam conformation was observed. It is proposed that the two complexes correspond to different stages along the deacylation path of the acyl-enzyme intermediate. The results provide a novel structural basis for the rational design of new β-lactamase inhibitors.
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10
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Avery C, Baker L, Jacobs DJ. Functional Dynamics of Substrate Recognition in TEM Beta-Lactamase. ENTROPY 2022; 24:e24050729. [PMID: 35626612 PMCID: PMC9140794 DOI: 10.3390/e24050729] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 02/01/2023]
Abstract
The beta-lactamase enzyme provides effective resistance to beta-lactam antibiotics due to substrate recognition controlled by point mutations. Recently, extended-spectrum and inhibitor-resistant mutants have become a global health problem. Here, the functional dynamics that control substrate recognition in TEM beta-lactamase are investigated using all-atom molecular dynamics simulations. Comparisons are made between wild-type TEM-1 and TEM-2 and the extended-spectrum mutants TEM-10 and TEM-52, both in apo form and in complex with four different antibiotics (ampicillin, amoxicillin, cefotaxime and ceftazidime). Dynamic allostery is predicted based on a quasi-harmonic normal mode analysis using a perturbation scan. An allosteric mechanism known to inhibit enzymatic function in TEM beta-lactamase is identified, along with other allosteric binding targets. Mechanisms for substrate recognition are elucidated using multivariate comparative analysis of molecular dynamics trajectories to identify changes in dynamics resulting from point mutations and ligand binding, and the conserved dynamics, which are functionally important, are extracted as well. The results suggest that the H10-H11 loop (residues 214-221) is a secondary anchor for larger extended spectrum ligands, while the H9-H10 loop (residues 194-202) is distal from the active site and stabilizes the protein against structural changes. These secondary non-catalytically-active loops offer attractive targets for novel noncompetitive inhibitors of TEM beta-lactamase.
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Affiliation(s)
- Chris Avery
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; (C.A.); (L.B.)
| | - Lonnie Baker
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; (C.A.); (L.B.)
| | - Donald J. Jacobs
- Department of Physics and Optical Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
- Correspondence:
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11
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Santos-Martin C, Wang G, Subedi P, Hor L, Totsika M, Paxman JJ, Heras B. Structural bioinformatic analysis of DsbA proteins and their pathogenicity associated substrates. Comput Struct Biotechnol J 2021; 19:4725-4737. [PMID: 34504665 PMCID: PMC8405906 DOI: 10.1016/j.csbj.2021.08.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 08/12/2021] [Accepted: 08/12/2021] [Indexed: 01/02/2023] Open
Abstract
The disulfide bond (DSB) forming system and in particular DsbA, is a key bacterial oxidative folding catalyst. Due to its role in promoting the correct assembly of a wide range of virulence factors required at different stages of the infection process, DsbA is a master virulence rheostat, making it an attractive target for the development of new virulence blockers. Although DSB systems have been extensively studied across different bacterial species, to date, little is known about how DsbA oxidoreductases are able to recognize and interact with such a wide range of substrates. This review summarizes the current knowledge on the DsbA enzymes, with special attention on their interaction with the partner oxidase DsbB and substrates associated with bacterial virulence. The structurally and functionally diverse set of bacterial proteins that rely on DsbA-mediated disulfide bond formation are summarized. Local sequence and secondary structure elements of these substrates are analyzed to identify common elements recognized by DsbA enzymes. This not only provides information on protein folding systems in bacteria but also offers tools for identifying new DsbA substrates and informs current efforts aimed at developing DsbA targeted anti-microbials.
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Affiliation(s)
- Carlos Santos-Martin
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Geqing Wang
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Pramod Subedi
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Lilian Hor
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Makrina Totsika
- Centre for Immunology and Infection Control, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia
| | - Jason John Paxman
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
| | - Begoña Heras
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Australia
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12
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Stewart NK, Toth M, Stasyuk A, Lee M, Smith CA, Vakulenko SB. Inhibition of the Clostridioides difficile Class D β-Lactamase CDD-1 by Avibactam. ACS Infect Dis 2021; 7:1164-1176. [PMID: 33390002 PMCID: PMC8826747 DOI: 10.1021/acsinfecdis.0c00714] [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] [Indexed: 12/15/2022]
Abstract
Avibactam is a potent diazobicyclooctane inhibitor of class A and C β-lactamases. The inhibitor also exhibits variable activity against some class D enzymes from Gram-negative bacteria; however, its interaction with recently discovered class D β-lactamases from Gram-positive bacteria has not been studied. Here, we describe microbiological, kinetic, and mass spectrometry studies of the interaction of avibactam with CDD-1, a class D β-lactamase from the clinically important pathogen Clostridioides difficile, and show that avibactam is a potent irreversible mechanism-based inhibitor of the enzyme. X-ray crystallographic studies at three time-points demonstrate the rapid formation of a stable CDD-1-avibactam acyl-enzyme complex and highlight differences in the anchoring of the inhibitor by class D enzymes from Gram-positive and Gram-negative bacteria.
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Affiliation(s)
- Nichole K Stewart
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Marta Toth
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Anastasiya Stasyuk
- Stanford Synchrotron Radiation Lightsource, Stanford University, Menlo Park, California 94025, United States
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Clyde A Smith
- Stanford Synchrotron Radiation Lightsource, Stanford University, Menlo Park, California 94025, United States
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Sergei B Vakulenko
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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13
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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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14
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Oliveira ASF, Ciccotti G, Haider S, Mulholland AJ. Dynamical nonequilibrium molecular dynamics reveals the structural basis for allostery and signal propagation in biomolecular systems. THE EUROPEAN PHYSICAL JOURNAL. B 2021; 94:144. [PMID: 34720710 PMCID: PMC8549953 DOI: 10.1140/epjb/s10051-021-00157-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/05/2021] [Indexed: 05/03/2023]
Abstract
ABSTRACT A dynamical approach to nonequilibrium molecular dynamics (D-NEMD), proposed in the 1970s by Ciccotti et al., is undergoing a renaissance and is having increasing impact in the study of biological macromolecules. This D-NEMD approach, combining MD simulations in stationary (in particular, equilibrium) and nonequilibrium conditions, allows for the determination of the time-dependent structural response of a system using the Kubo-Onsager relation. Besides providing a detailed picture of the system's dynamic structural response to an external perturbation, this approach also has the advantage that the statistical significance of the response can be assessed. The D-NEMD approach has been used recently to identify a general mechanism of inter-domain signal propagation in nicotinic acetylcholine receptors, and allosteric effects in β -lactamase enzymes, for example. It complements equilibrium MD and is a very promising approach to identifying and analysing allosteric effects. Here, we review the D-NEMD approach and its application to biomolecular systems, including transporters, receptors, and enzymes.
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Affiliation(s)
- A. Sofia F. Oliveira
- School of Chemistry, Centre for Computational Chemistry, University of Bristol, Bristol, BS8 1TS UK
- BrisSynBio, Life Sciences Building, Tyndall Avenue, Bristol, BS8 1TQ UK
| | - Giovanni Ciccotti
- Institute for Applied Computing “Mauro Picone” (IAC), CNR, Via dei Taurini 19, 00185 Rome, Italy
- School of Physics, University College of Dublin, UCD-Belfield, Dublin 4, Ireland
- Università di Roma La Sapienza, Ple. A. Moro 5, 00185 Rome, Italy
| | - Shozeb Haider
- School of Pharmacy, University College London, London, WC1N 1AX UK
| | - Adrian J. Mulholland
- School of Chemistry, Centre for Computational Chemistry, University of Bristol, Bristol, BS8 1TS UK
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15
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Mehta SC, Furey IM, Pemberton OA, Boragine DM, Chen Y, Palzkill T. KPC-2 β-lactamase enables carbapenem antibiotic resistance through fast deacylation of the covalent intermediate. J Biol Chem 2021; 296:100155. [PMID: 33273017 PMCID: PMC7895804 DOI: 10.1074/jbc.ra120.015050] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 11/24/2020] [Accepted: 12/03/2020] [Indexed: 01/23/2023] Open
Abstract
Serine active-site β-lactamases hydrolyze β-lactam antibiotics through the formation of a covalent acyl-enzyme intermediate followed by deacylation via an activated water molecule. Carbapenem antibiotics are poorly hydrolyzed by most β-lactamases owing to slow hydrolysis of the acyl-enzyme intermediate. However, the emergence of the KPC-2 carbapenemase has resulted in widespread resistance to these drugs, suggesting it operates more efficiently. Here, we investigated the unusual features of KPC-2 that enable this resistance. We show that KPC-2 has a 20,000-fold increased deacylation rate compared with the common TEM-1 β-lactamase. Furthermore, kinetic analysis of active site alanine mutants indicates that carbapenem hydrolysis is a concerted effort involving multiple residues. Substitution of Asn170 greatly decreases the deacylation rate, but this residue is conserved in both KPC-2 and non-carbapenemase β-lactamases, suggesting it promotes carbapenem hydrolysis only in the context of KPC-2. X-ray structure determination of the N170A enzyme in complex with hydrolyzed imipenem suggests Asn170 may prevent the inactivation of the deacylating water by the 6α-hydroxyethyl substituent of carbapenems. In addition, the Thr235 residue, which interacts with the C3 carboxylate of carbapenems, also contributes strongly to the deacylation reaction. In contrast, mutation of the Arg220 and Thr237 residues decreases the acylation rate and, paradoxically, improves binding affinity for carbapenems. Thus, the role of these residues may be ground state destabilization of the enzyme-substrate complex or, alternatively, to ensure proper alignment of the substrate with key catalytic residues to facilitate acylation. These findings suggest modifications of the carbapenem scaffold to avoid hydrolysis by KPC-2 β-lactamase.
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Affiliation(s)
- Shrenik C Mehta
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Ian M Furey
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Orville A Pemberton
- Department of Molecular Medicine, University of South Florida Morsani College of Medicine, Tampa, Florida, USA
| | - David M Boragine
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Yu Chen
- Department of Molecular Medicine, University of South Florida Morsani College of Medicine, Tampa, Florida, USA
| | - Timothy Palzkill
- Department of Pharmacology and Chemical Biology, Baylor College of Medicine, Houston, Texas, USA.
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16
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Cao TP, Yi H, Dhanasingh I, Ghosh S, Choi JM, Lee KH, Ryu S, Kim HS, Lee SH. Non-catalytic-Region Mutations Conferring Transition of Class A β-Lactamases Into ESBLs. Front Mol Biosci 2020; 7:598998. [PMID: 33335913 PMCID: PMC7737660 DOI: 10.3389/fmolb.2020.598998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/28/2020] [Indexed: 12/03/2022] Open
Abstract
Despite class A ESBLs carrying substitutions outside catalytic regions, such as Cys69Tyr or Asn136Asp, have emerged as new clinical threats, the molecular mechanisms underlying their acquired antibiotics-hydrolytic activity remains unclear. We discovered that this non-catalytic-region (NCR) mutations induce significant dislocation of β3-β4 strands, conformational changes in critical residues associated with ligand binding to the lid domain, dynamic fluctuation of Ω-loop and β3-β4 elements. Such structural changes increase catalytic regions’ flexibility, enlarge active site, and thereby accommodate third-generation cephalosporin antibiotics, ceftazidime (CAZ). Notably, the electrostatic property around the oxyanion hole of Cys69Tyr ESBL is significantly changed, resulting in possible additional stabilization of the acyl-enzyme intermediate. Interestingly, the NCR mutations are as effective for antibiotic resistance by altering the structure and dynamics in regions mediating substrate recognition and binding as single amino-acid substitutions in the catalytic region of the canonical ESBLs. We believe that our findings are crucial in developing successful therapeutic strategies against diverse class A ESBLs, including the new NCR-ESBLs.
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Affiliation(s)
- Thinh-Phat Cao
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea.,Department of Biomedical Sciences, Gwangju Alzheimer's Disease and Related Dementia Cohort Research Center, College of Natural Sciences and Public Health and Safety, Chosun University, Gwangju, South Korea
| | - Hyojeong Yi
- Division of Biosystems & Biomedical Sciences, College of Health Sciences, Korea University, Seoul, South Korea
| | - Immanuel Dhanasingh
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea
| | - Suparna Ghosh
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea
| | - Jin Myung Choi
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea
| | - Kun Ho Lee
- Department of Biomedical Sciences, Gwangju Alzheimer's Disease and Related Dementia Cohort Research Center, College of Natural Sciences and Public Health and Safety, Chosun University, Gwangju, South Korea.,Aging Neuroscience Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Seol Ryu
- Department of Chemistry, Chosun University, Gwangju, South Korea
| | - Heenam Stanley Kim
- Division of Biosystems & Biomedical Sciences, College of Health Sciences, Korea University, Seoul, South Korea
| | - Sung Haeng Lee
- Department of Cellular and Molecular Medicine, Chosun University School of Medicine, Gwangju, South Korea.,Department of Biomedical Sciences, Gwangju Alzheimer's Disease and Related Dementia Cohort Research Center, College of Natural Sciences and Public Health and Safety, Chosun University, Gwangju, South Korea
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17
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Song Z, Zhou H, Tian H, Wang X, Tao P. Unraveling the energetic significance of chemical events in enzyme catalysis via machine-learning based regression approach. Commun Chem 2020; 3:134. [PMID: 36703376 PMCID: PMC9814854 DOI: 10.1038/s42004-020-00379-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 09/11/2020] [Indexed: 01/29/2023] Open
Abstract
The bacterial enzyme class of β-lactamases are involved in benzylpenicillin acylation reactions, which are currently being revisited using hybrid quantum mechanical molecular mechanical (QM/MM) chain-of-states pathway optimizations. Minimum energy pathways are sampled by reoptimizing pathway geometry under different representative protein environments obtained through constrained molecular dynamics simulations. Predictive potential energy surface models in the reaction space are trained with machine-learning regression techniques. Herein, using TEM-1/benzylpenicillin acylation reaction as the model system, we introduce two model-independent criteria for delineating the energetic contributions and correlations in the predicted reaction space. Both methods are demonstrated to effectively quantify the energetic contribution of each chemical process and identify the rate limiting step of enzymatic reaction with high degrees of freedom. The consistency of the current workflow is tested under seven levels of quantum chemistry theory and three non-linear machine-learning regression models. The proposed approaches are validated to provide qualitative compliance with experimental mutagenesis studies.
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Affiliation(s)
- Zilin Song
- grid.263864.d0000 0004 1936 7929Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX 75275 USA
| | - Hongyu Zhou
- grid.263864.d0000 0004 1936 7929Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX 75275 USA
| | - Hao Tian
- grid.263864.d0000 0004 1936 7929Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX 75275 USA
| | - Xinlei Wang
- grid.263864.d0000 0004 1936 7929Department of Statistical Science, Southern Methodist University, Dallas, TX 75275 USA
| | - Peng Tao
- grid.263864.d0000 0004 1936 7929Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX 75275 USA
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18
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Structural Basis and Binding Kinetics of Vaborbactam in Class A β-Lactamase Inhibition. Antimicrob Agents Chemother 2020; 64:AAC.00398-20. [PMID: 32778546 DOI: 10.1128/aac.00398-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 07/31/2020] [Indexed: 12/20/2022] Open
Abstract
Class A β-lactamases are a major cause of β-lactam resistance in Gram-negative bacteria. The recently FDA-approved cyclic boronate vaborbactam is a reversible covalent inhibitor of class A β-lactamases, including CTX-M extended-spectrum β-lactamase and KPC carbapenemase, both frequently observed in the clinic. Intriguingly, vaborbactam displayed different binding kinetics and cell-based activity for these two enzymes, despite their similarity. A 1.0-Å crystal structure of CTX-M-14 demonstrated that two catalytic residues, K73 and E166, are positively charged and neutral, respectively. Meanwhile, a 1.25-Å crystal structure of KPC-2 revealed a more compact binding mode of vaborbactam versus CTX-M-14, as well as alternative conformations of W105. Together with kinetic analysis of W105 mutants, the structures demonstrate the influence of this residue and the unusual conformation of the β3 strand on the inactivation rate, as well as the stability of the reversible covalent bond with S70. Furthermore, studies of KPC-2 S130G mutant shed light on the different impacts of S130 in the binding of vaborbactam versus avibactam, another recently approved β-lactamase inhibitor. Taken together, these new data provide valuable insights into the inhibition mechanism of vaborbactam and future development of cyclic boronate inhibitors.
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19
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Langan PS, Sullivan B, Weiss KL, Coates L. Probing the role of the conserved residue Glu166 in a class A β-lactamase using neutron and X-ray protein crystallography. Acta Crystallogr D Struct Biol 2020; 76:118-123. [PMID: 32038042 PMCID: PMC7008513 DOI: 10.1107/s2059798319016334] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/03/2019] [Indexed: 11/10/2022] Open
Abstract
The amino-acid sequence of the Toho-1 β-lactamase contains several conserved residues in the active site, including Ser70, Lys73, Ser130 and Glu166, some of which coordinate a catalytic water molecule. This catalytic water molecule is essential in the acylation and deacylation parts of the reaction mechanism through which Toho-1 inactivates specific antibiotics and provides resistance to its expressing bacterial strains. To investigate the function of Glu166 in the acylation part of the catalytic mechanism, neutron and X-ray crystallographic studies were performed on a Glu166Gln mutant. The structure of this class A β-lactamase mutant provides several insights into its previously reported reduced drug-binding kinetic rates. A joint refinement of both X-ray and neutron diffraction data was used to study the effects of the Glu166Gln mutation on the active site of Toho-1. This structure reveals that while the Glu166Gln mutation has a somewhat limited impact on the positions of the conserved amino acids within the active site, it displaces the catalytic water molecule from the active site. These subtle changes offer a structural explanation for the previously observed decreases in the binding of non-β-lactam inhibitors such as the recently developed diazobicyclooctane inhibitor avibactam.
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Affiliation(s)
- Patricia S. Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Brendan Sullivan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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20
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Influence of the α-Methoxy Group on the Reaction of Temocillin with Pseudomonas aeruginosa PBP3 and CTX-M-14 β-Lactamase. Antimicrob Agents Chemother 2019; 64:AAC.01473-19. [PMID: 31685462 DOI: 10.1128/aac.01473-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/14/2019] [Indexed: 12/26/2022] Open
Abstract
The prevalence of multidrug-resistant Pseudomonas aeruginosa has led to the reexamination of older "forgotten" drugs, such as temocillin, for their ability to combat resistant microbes. Temocillin is the 6-α-methoxy analogue of ticarcillin, a carboxypenicillin with well-characterized antipseudomonal properties. The α-methoxy modification confers resistance to serine β-lactamases, yet temocillin is ineffective against P. aeruginosa growth. The origins of temocillin's inferior antibacterial properties against P. aeruginosa have remained relatively unexplored. Here, we analyze the reaction kinetics, protein stability, and binding conformations of temocillin and ticarcillin with penicillin-binding protein 3 (PBP3), an essential PBP in P. aeruginosa We show that the 6-α-methoxy group perturbs the stability of the PBP3 acyl-enzyme, which manifests in an elevated off-rate constant (k off) in biochemical assays comparing temocillin with ticarcillin. Complex crystal structures with PBP3 reveal similar binding modes of the two drugs but with important differences. Most notably, the 6-α-methoxy group disrupts a high-quality hydrogen bond with a conserved residue important for ligand binding while also being inserted into a crowded active site, possibly destabilizing the active site and enabling water molecule from bulk solvent to access and cleave the acyl-enzyme bond. This hypothesis is supported by the observation that the acyl-enzyme complex of temocillin has reduced thermal stability compared with ticarcillin. Furthermore, we explore temocillin's mechanism of β-lactamase inhibition with a high-resolution complex structure of CTX-M-14 class A serine β-lactamase. The results suggest that the α-methoxy group prevents hydrolysis by locking the compound into an unexpected conformation that impedes access of the catalytic water to the acyl-enzyme adduct.
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21
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Au HW, Tsang MW, So PK, Wong KY, Leung YC. Thermostable β-Lactamase Mutant with Its Active Site Conjugated with Fluorescein for Efficient β-Lactam Antibiotic Detection. ACS OMEGA 2019; 4:20493-20502. [PMID: 31858033 PMCID: PMC6906784 DOI: 10.1021/acsomega.9b02211] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/14/2019] [Indexed: 05/09/2023]
Abstract
Monitoring the β-lactam antibiotic level has been an important task in food industry and clinical practice. Here, we report the development of a fluorescent PenP β-lactamase, PenP-E166Cf/N170Q, for efficient β-lactam antibiotic detection. It was constructed by covalently attaching fluorescein onto the active-site entrance of a thermostable E166Cf/N170Q mutant of a Bacillus licheniformis PenP β-lactamase. It gave a fluorescence turn-on signal toward various β-lactam antibiotics, where the fluorescence enhancement was attributed to the acyl-enzyme complex formed between PenP-E166Cf/N170Q and the β-lactam antibiotic. It demonstrated enhanced signal stability over its parental PenP-E166Cf because of the suppressed hydrolytic activity by the N170Q mutation. Compared with our previously constructed PenPC-E166Cf biosensor, PenP-E166Cf/N170Q was more thermostable and advanced in detecting β-lactams in terms of response time, signal stability, and detection limit. Positive fluorescence signals generated by E166Cf/N170Q in response to the penicillin-containing milk and mouse serum illustrated the feasibility of the biosensor for antibiotic detection in real samples. Taken together, our findings suggest the potential application of PenP-E166Cf/N170Q in biosensing β-lactam antibiotics.
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Affiliation(s)
- Ho-Wah Au
- Department
of Applied Biology and Chemical Technology, State Key
Laboratory of Chemical Biology and Drug Discovery and Lo Ka Chung Research Centre for
Natural Anti-Cancer Drug Development, The
Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Man-Wah Tsang
- Department
of Applied Biology and Chemical Technology, State Key
Laboratory of Chemical Biology and Drug Discovery and Lo Ka Chung Research Centre for
Natural Anti-Cancer Drug Development, The
Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Pui-Kin So
- Department
of Applied Biology and Chemical Technology, State Key
Laboratory of Chemical Biology and Drug Discovery and Lo Ka Chung Research Centre for
Natural Anti-Cancer Drug Development, The
Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Kwok-Yin Wong
- Department
of Applied Biology and Chemical Technology, State Key
Laboratory of Chemical Biology and Drug Discovery and Lo Ka Chung Research Centre for
Natural Anti-Cancer Drug Development, The
Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
- E-mail: (K.-Y.W.)
| | - Yun-Chung Leung
- Department
of Applied Biology and Chemical Technology, State Key
Laboratory of Chemical Biology and Drug Discovery and Lo Ka Chung Research Centre for
Natural Anti-Cancer Drug Development, The
Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
- E-mail: (Y.-C.L.)
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22
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Knox R, Lento C, Wilson DJ. Mapping Conformational Dynamics to Individual Steps in the TEM-1 β-Lactamase Catalytic Mechanism. J Mol Biol 2018; 430:3311-3322. [PMID: 29964048 DOI: 10.1016/j.jmb.2018.06.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/14/2018] [Accepted: 06/22/2018] [Indexed: 10/28/2022]
Abstract
Conformational dynamics are increasingly recognized as being essential for enzyme function. However, there is virtually no direct experimental evidence to support the notion that individual dynamic modes are required for specific catalytic processes, apart from the initial step of substrate binding. In this work, we use a unique approach based on millisecond hydrogen-deuterium exchange mass spectrometry to identify dynamic modes linked to individual catalytic processes in the antibiotic resistance enzyme TEM-1 β-lactamase. Using a "good" substrate (ampicillin), a poorly hydrolyzed substrate (cephalexin) and a covalent inhibitor (clavulanate), we are able to isolate dynamic modes that are specifically linked to substrate binding, productive lactam ring hydrolysis and deacylation. These discoveries are ultimately translated into specific targets for allosteric TEM-1 inhibitor development.
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Affiliation(s)
- Ruth Knox
- Department of Chemistry, York University, Toronto, Canada M3J 1P3
| | - Cristina Lento
- Department of Chemistry, York University, Toronto, Canada M3J 1P3
| | - Derek J Wilson
- Department of Chemistry, York University, Toronto, Canada M3J 1P3; Center for Research in Mass Spectrometry, York University, Toronto, Canada M3J 1P3.
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23
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Schmuck B, Sandgren M, Härd T. The kinetics of TEM1 antibiotic degrading enzymes that are displayed on Ure2 protein nanofibrils in a flow reactor. PLoS One 2018; 13:e0196250. [PMID: 29684061 PMCID: PMC5912753 DOI: 10.1371/journal.pone.0196250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/09/2018] [Indexed: 01/31/2023] Open
Abstract
Enzymatic functionalization of cross-β structured protein nanofibrils has hitherto resulted in a severe reduction of the catalytic efficiency of high turnover biocatalysts. It has been speculated that steric restrictions and mass transport pose limits on the attached enzymes, but detailed kinetics analyzing this have not yet been reported. For a more comprehensive understanding, we studied protein nanofibrils endowed with TEM1, a β-lactamase from Escherichia coli. The packing density of TEM1 along the fibrils was controlled by co-fibrillation; in other words, the N-terminal ureidosuccinate transporter Ure2(1–80) from Saccharomyces cerevisiae was simultaneously aggregated with the chimeric proteins TEM1-Ure2(1–80). The mature fibrils were trapped in a column, and the rate of ampicillin hydrolysis was recorded using a continuous substrate flow. The turnover rate was plotted as a function of substrate molecules available per enzyme per second, which demonstrated that an elevated substrate availability counteracts mass transport limitations. To analyze this data set, we derived a kinetic model, which makes it possible to easily characterize and compare enzymes packed in columns. The functional TEM1 nanofibrils possess 80% of the catalytic turnover rate compared to free TEM1 in solution. Altogether, we have created protein nanofibrils that can effectively hydrolyze β-lactam antibiotic contaminations and provided a groundwork strategy for other highly functional enzymatic nanofibrils.
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Affiliation(s)
- Benjamin Schmuck
- Department of Molecular Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Torleif Härd
- Department of Molecular Sciences, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
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24
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Langan PS, Vandavasi VG, Cooper CJ, Weiss KL, Ginell SL, Parks JM, Coates L. Substrate Binding Induces Conformational Changes in a Class A β-lactamase That Prime It for Catalysis. ACS Catal 2018. [DOI: 10.1021/acscatal.7b04114] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Patricia S. Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Venu Gopal Vandavasi
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Connor J. Cooper
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Stephan L. Ginell
- Structural Biology Center, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, United States
| | - Jerry M. Parks
- Graduate School of Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6309, United States
| | - Leighton Coates
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
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25
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Dellus-Gur E, Elias M, Caselli E, Prati F, Salverda MLM, de Visser JAGM, Fraser JS, Tawfik DS. Negative Epistasis and Evolvability in TEM-1 β-Lactamase--The Thin Line between an Enzyme's Conformational Freedom and Disorder. J Mol Biol 2015; 427:2396-409. [PMID: 26004540 DOI: 10.1016/j.jmb.2015.05.011] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 05/08/2015] [Accepted: 05/12/2015] [Indexed: 12/28/2022]
Abstract
Epistasis is a key factor in evolution since it determines which combinations of mutations provide adaptive solutions and which mutational pathways toward these solutions are accessible by natural selection. There is growing evidence for the pervasiveness of sign epistasis--a complete reversion of mutational effects, particularly in protein evolution--yet its molecular basis remains poorly understood. We describe the structural basis of sign epistasis between G238S and R164S, two adaptive mutations in TEM-1 β-lactamase--an enzyme that endows antibiotics resistance. Separated by 10 Å, these mutations initiate two separate trajectories toward increased hydrolysis rates and resistance toward second and third-generation cephalosporins antibiotics. Both mutations allow the enzyme's active site to adopt alternative conformations and accommodate the new antibiotics. By solving the corresponding set of crystal structures, we found that R164S causes local disorder whereas G238S induces discrete conformations. When combined, the mutations in 238 and 164 induce local disorder whereby nonproductive conformations that perturb the enzyme's catalytic preorganization dominate. Specifically, Asn170 that coordinates the deacylating water molecule is misaligned, in both the free form and the inhibitor-bound double mutant. This local disorder is not restored by stabilizing global suppressor mutations and thus leads to an evolutionary cul-de-sac. Conformational dynamism therefore underlines the reshaping potential of protein's structures and functions but also limits protein evolvability because of the fragility of the interactions networks that maintain protein structures.
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Affiliation(s)
- Eynat Dellus-Gur
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Mikael Elias
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Emilia Caselli
- Department of Chemistry, University of Modena, Modena 41100, Italy
| | - Fabio Prati
- Department of Chemistry, University of Modena, Modena 41100, Italy
| | - Merijn L M Salverda
- Institute for Translational Vaccinology (Intravacc), Bilthoven 3720 AL, The Netherlands
| | - J Arjan G M de Visser
- Laboratory of Genetics, Department of Plant Sciences, Wageningen University, Wageningen 6700 AH, The Netherlands
| | - James S Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, CA 94143, USA.
| | - Dan S Tawfik
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
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26
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Exploring the potential impact of an expanded genetic code on protein function. Proc Natl Acad Sci U S A 2015; 112:6961-6. [PMID: 26038548 DOI: 10.1073/pnas.1507741112] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
With few exceptions, all living organisms encode the same 20 canonical amino acids; however, it remains an open question whether organisms with additional amino acids beyond the common 20 might have an evolutionary advantage. Here, we begin to test that notion by making a large library of mutant enzymes in which 10 structurally distinct noncanonical amino acids were substituted at single sites randomly throughout TEM-1 β-lactamase. A screen for growth on the β-lactam antibiotic cephalexin afforded a unique p-acrylamido-phenylalanine (AcrF) mutation at Val-216 that leads to an increase in catalytic efficiency by increasing kcat, but not significantly affecting KM. To understand the structural basis for this enhanced activity, we solved the X-ray crystal structures of the ligand-free mutant enzyme and of the deacylation-defective wild-type and mutant cephalexin acyl-enzyme intermediates. These structures show that the Val-216-AcrF mutation leads to conformational changes in key active site residues-both in the free enzyme and upon formation of the acyl-enzyme intermediate-that lower the free energy of activation of the substrate transacylation reaction. The functional changes induced by this mutation could not be reproduced by substitution of any of the 20 canonical amino acids for Val-216, indicating that an expanded genetic code may offer novel solutions to proteins as they evolve new activities.
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27
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Stojanoski V, Chow DC, Hu L, Sankaran B, Gilbert HF, Prasad BVV, Palzkill T. A triple mutant in the Ω-loop of TEM-1 β-lactamase changes the substrate profile via a large conformational change and an altered general base for catalysis. J Biol Chem 2015; 290:10382-94. [PMID: 25713062 DOI: 10.1074/jbc.m114.633438] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Indexed: 11/06/2022] Open
Abstract
β-Lactamases are bacterial enzymes that hydrolyze β-lactam antibiotics. TEM-1 is a prevalent plasmid-encoded β-lactamase in Gram-negative bacteria that efficiently catalyzes the hydrolysis of penicillins and early cephalosporins but not oxyimino-cephalosporins. A previous random mutagenesis study identified a W165Y/E166Y/P167G triple mutant that displays greatly altered substrate specificity with increased activity for the oxyimino-cephalosporin, ceftazidime, and decreased activity toward all other β-lactams tested. Surprisingly, this mutant lacks the conserved Glu-166 residue critical for enzyme function. Ceftazidime contains a large, bulky side chain that does not fit optimally in the wild-type TEM-1 active site. Therefore, it was hypothesized that the substitutions in the mutant expand the binding site in the enzyme. To investigate structural changes and address whether there is an enlargement in the active site, the crystal structure of the triple mutant was solved to 1.44 Å. The structure reveals a large conformational change of the active site Ω-loop structure to create additional space for the ceftazidime side chain. The position of the hydroxyl group of Tyr-166 and an observed shift in the pH profile of the triple mutant suggests that Tyr-166 participates in the hydrolytic mechanism of the enzyme. These findings indicate that the highly conserved Glu-166 residue can be substituted in the mechanism of serine β-lactamases. The results reveal that the robustness of the overall β-lactamase fold coupled with the plasticity of an active site loop facilitates the evolution of enzyme specificity and mechanism.
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Affiliation(s)
- Vlatko Stojanoski
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and the Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030 and
| | - Dar-Chone Chow
- the Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030 and
| | - Liya Hu
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and
| | - Banumathi Sankaran
- the Berkeley Center for Structural Biology, Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Hiram F Gilbert
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and
| | - B V Venkataram Prasad
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and
| | - Timothy Palzkill
- From the Verna and Marrs McLean Department of Biochemistry and Molecular Biology and the Department of Pharmacology, Baylor College of Medicine, Houston, Texas 77030 and
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28
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Levitt PS, Papp-Wallace KM, Taracila MA, Hujer AM, Winkler ML, Smith KM, Xu Y, Harris ME, Bonomo RA. Exploring the role of a conserved class A residue in the Ω-Loop of KPC-2 β-lactamase: a mechanism for ceftazidime hydrolysis. J Biol Chem 2012; 287:31783-93. [PMID: 22843686 DOI: 10.1074/jbc.m112.348540] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gram-negative bacteria harboring KPC-2, a class A β-lactamase, are resistant to all β-lactam antibiotics and pose a major public health threat. Arg-164 is a conserved residue in all class A β-lactamases and is located in the solvent-exposed Ω-loop of KPC-2. To probe the role of this amino acid in KPC-2, we performed site-saturation mutagenesis. When compared with wild type, 11 of 19 variants at position Arg-164 in KPC-2 conferred increased resistance to the oxyimino-cephalosporin, ceftazidime (minimum inhibitory concentration; 32→128 mg/liter) when expressed in Escherichia coli. Using the R164S variant of KPC-2 as a representative β-lactamase for more detailed analysis, we observed only a modest 25% increase in k(cat)/K(m) for ceftazidime (0.015→0.019 μm(-1) s(-1)). Employing pre-steady-state kinetics and mass spectrometry, we determined that acylation is rate-limiting for ceftazidime hydrolysis by KPC-2, whereas deacylation is rate-limiting in the R164S variant, leading to accumulation of acyl-enzyme at steady-state. CD spectroscopy revealed that a conformational change occurred in the turnover of ceftazidime by KPC-2, but not the R164S variant, providing evidence for a different form of the enzyme at steady state. Molecular models constructed to explain these findings suggest that ceftazidime adopts a unique conformation, despite preservation of Ω-loop structure. We propose that the R164S substitution in KPC-2 enhances ceftazidime resistance by proceeding through "covalent trapping" of the substrate by a deacylation impaired enzyme with a lower K(m). Future antibiotic design must consider the distinctive behavior of the Ω-loop of KPC-2.
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Affiliation(s)
- Peter S Levitt
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106, USA
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29
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Chakraborty S. Enumerating pathways of proton abstraction based on a spatial and electrostatic analysis of residues in the catalytic site. PLoS One 2012; 7:e39577. [PMID: 22745790 PMCID: PMC3379984 DOI: 10.1371/journal.pone.0039577] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 05/28/2012] [Indexed: 11/19/2022] Open
Abstract
The pathways of proton abstraction (PA), a key aspect of most catalytic reactions, is often controversial and highly debated. Ultrahigh-resolution diffraction studies, molecular dynamics, quantum mechanics and molecular mechanic simulations are often adopted to gain insights in the PA mechanisms in enzymes. These methods require expertise and effort to setup and can be computationally intensive. We present a push button methodology--Proton abstraction Simulation (PRISM)--to enumerate the possible pathways of PA in a protein with known 3D structure based on the spatial and electrostatic properties of residues in the proximity of a given nucleophilic residue. Proton movements are evaluated in the vicinity of this nucleophilic residue based on distances, potential differences, spatial channels and characteristics of the individual residues (polarity, acidic, basic, etc). Modulating these parameters eliminates their empirical nature and also might reveal pathways that originate from conformational changes. We have validated our method using serine proteases and concurred with the dichotomy in PA in Class A β-lactamases, both of which are hydrolases. The PA mechanism in a transferase has also been corroborated. The source code is made available at www.sanchak.com/prism.
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Affiliation(s)
- Sandeep Chakraborty
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, India.
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30
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Lerner TR, Lovering AL, Bui NK, Uchida K, Aizawa SI, Vollmer W, Sockett RE. Specialized peptidoglycan hydrolases sculpt the intra-bacterial niche of predatory Bdellovibrio and increase population fitness. PLoS Pathog 2012; 8:e1002524. [PMID: 22346754 PMCID: PMC3276566 DOI: 10.1371/journal.ppat.1002524] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 12/21/2011] [Indexed: 11/18/2022] Open
Abstract
Bdellovibrio are predatory bacteria that have evolved to invade virtually all Gram-negative bacteria, including many prominent pathogens. Upon invasion, prey bacteria become rounded up into an osmotically stable niche for the Bdellovibrio, preventing further superinfection and allowing Bdellovibrio to replicate inside without competition, killing the prey bacterium and degrading its contents. Historically, prey rounding was hypothesized to be associated with peptidoglycan (PG) metabolism; we found two Bdellovibrio genes, bd0816 and bd3459, expressed at prey entry and encoding proteins with limited homologies to conventional dacB/PBP4 DD-endo/carboxypeptidases (responsible for peptidoglycan maintenance during growth and division). We tested possible links between Bd0816/3459 activity and predation. Bd3459, but not an active site serine mutant protein, bound β-lactam, exhibited DD-endo/carboxypeptidase activity against purified peptidoglycan and, importantly, rounded up E. coli cells upon periplasmic expression. A ΔBd0816 ΔBd3459 double mutant invaded prey more slowly than the wild type (with negligible prey cell rounding) and double invasions of single prey by more than one Bdellovibrio became more frequent. We solved the crystal structure of Bd3459 to 1.45 Å and this revealed predation-associated domain differences to conventional PBP4 housekeeping enzymes (loss of the regulatory domain III, alteration of domain II and a more exposed active site). The Bd3459 active site (and by similarity the Bd0816 active site) can thus accommodate and remodel the various bacterial PGs that Bdellovibrio may encounter across its diverse prey range, compared to the more closed active site that “regular” PBP4s have for self cell wall maintenance. Therefore, during evolution, Bdellovibrio peptidoglycan endopeptidases have adapted into secreted predation-specific proteins, preventing wasteful double invasion, and allowing activity upon the diverse prey peptidoglycan structures to sculpt the prey cell into a stable intracellular niche for replication. Bdellovibrio bacteriovorus is a small predatory bacterium that invades other bacteria including pathogens of humans and animals. Bdellovibrio digest the pathogens from within, growing at their expense. Bdellovibrio do not attack human, plant or animal cells and so could be applied as “living antibiotics”. Here we have discovered how Bdellovibrio evolved to live inside other bacteria. Evolution has changed (normally housekeeping) genes called dacBs so that their products recognise and modify the different cell walls of a wide range of bacteria. Their action sculpts the cell walls of the invaded bacteria to make a stable “home” for the Bdellovibrio, inside which it kills them. We know the structure and activity of the enzymes and that mutants without them are not as efficient predators. This is relevant to antibacterial therapies because the predatory DacB enzymes themselves act against bacteria and are also a key factor in Bdellovibrio cells being live predators of pathogens.
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Affiliation(s)
- Thomas R. Lerner
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, Medical School, Nottingham, United Kingdom
| | - Andrew L. Lovering
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Nhat Khai Bui
- The Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Kaoru Uchida
- Department of Life Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, Japan
| | - Shin-Ichi Aizawa
- Department of Life Sciences, Prefectural University of Hiroshima, Shobara, Hiroshima, Japan
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - R. Elizabeth Sockett
- Centre for Genetics and Genomics, School of Biology, University of Nottingham, Medical School, Nottingham, United Kingdom
- * E-mail:
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31
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Brown NG, Chow DC, Sankaran B, Zwart P, Prasad BVV, Palzkill T. Analysis of the binding forces driving the tight interactions between beta-lactamase inhibitory protein-II (BLIP-II) and class A beta-lactamases. J Biol Chem 2011; 286:32723-35. [PMID: 21775426 PMCID: PMC3173220 DOI: 10.1074/jbc.m111.265058] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 06/25/2011] [Indexed: 12/19/2022] Open
Abstract
β-Lactamases hydrolyze β-lactam antibiotics to provide drug resistance to bacteria. β-Lactamase inhibitory protein-II (BLIP-II) is a potent proteinaceous inhibitor that exhibits low picomolar affinity for class A β-lactamases. This study examines the driving forces for binding between BLIP-II and β-lactamases using a combination of presteady state kinetics, isothermal titration calorimetry, and x-ray crystallography. The measured dissociation rate constants for BLIP-II and various β-lactamases ranged from 10(-4) to 10(-7) s(-1) and are comparable with those found in some of the tightest known protein-protein interactions. The crystal structures of BLIP-II alone and in complex with Bacillus anthracis Bla1 β-lactamase revealed no significant side-chain movement in BLIP-II in the complex versus the monomer. The structural rigidity of BLIP-II minimizes the loss of the entropy upon complex formation and, as indicated by thermodynamics experiments, may be a key determinant of the observed potent inhibition of β-lactamases.
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Affiliation(s)
- Nicholas G. Brown
- From the Departments of Pharmacology
- Biochemistry and Molecular Biology, and
| | | | - Banumathi Sankaran
- The Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Peter Zwart
- The Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - B. V. Venkataram Prasad
- Biochemistry and Molecular Biology, and
- Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030 and
| | - Timothy Palzkill
- From the Departments of Pharmacology
- Biochemistry and Molecular Biology, and
- Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas 77030 and
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32
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Frase H, Smith CA, Toth M, Champion MM, Mobashery S, Vakulenko SB. Identification of products of inhibition of GES-2 beta-lactamase by tazobactam by x-ray crystallography and spectrometry. J Biol Chem 2011; 286:14396-409. [PMID: 21345789 PMCID: PMC3077639 DOI: 10.1074/jbc.m110.208744] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 01/19/2011] [Indexed: 01/28/2023] Open
Abstract
The GES-2 β-lactamase is a class A carbapenemase, the emergence of which in clinically important bacterial pathogens is a disconcerting development as the enzyme confers resistance to carbapenem antibiotics. Tazobactam is a clinically used inhibitor of class A β-lactamases, which inhibits the GES-2 enzyme effectively, restoring susceptibility to β-lactam antibiotics. We have investigated the details of the mechanism of inhibition of the GES-2 enzyme by tazobactam. By the use of UV spectrometry, mass spectroscopy, and x-ray crystallography, we have documented and identified the involvement of a total of seven distinct GES-2·tazobactam complexes and one product of the hydrolysis of tazobactam that contribute to the inhibition profile. The x-ray structures for the GES-2 enzyme are for both the native (1.45 Å) and the inhibited complex with tazobactam (1.65 Å). This is the first such structure of a carbapenemase in complex with a clinically important β-lactam inhibitor, shedding light on the structural implications for the inhibition process.
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Affiliation(s)
- Hilary Frase
- From the Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 and
| | - Clyde A. Smith
- the Stanford Synchrotron Radiation Laboratory, Stanford University, Menlo Park, California 94025
| | - Marta Toth
- From the Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 and
| | - Matthew M. Champion
- From the Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 and
| | - Shahriar Mobashery
- From the Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 and
| | - Sergei B. Vakulenko
- From the Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556 and
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33
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Delmas J, Leyssene D, Dubois D, Birck C, Vazeille E, Robin F, Bonnet R. Structural insights into substrate recognition and product expulsion in CTX-M enzymes. J Mol Biol 2010; 400:108-20. [PMID: 20452359 DOI: 10.1016/j.jmb.2010.04.062] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 11/25/2022]
Abstract
beta-Lactamase-mediated resistance to beta-lactam antibiotics poses a major threat to our antibiotic armamentarium. Among beta-lactamases, a significant threat comes from enzymes that hydrolyze extended-spectrum cephalosporins such as cefotaxime. Among the enzymes that exhibit this phenotype, the CTX-M family is found worldwide. These enzymes have a small active site, which makes it difficult to explain how they hydrolyze the bulky extended-spectrum cephalosporins into the binding site. We investigated noncovalent substrate recognition and product release in CTX-M enzymes using steered molecular dynamics simulation and X-ray diffraction. An arginine residue located far from the binding site favors the capture and tracking of substrates during entrance into the catalytic pocket. We show that the accommodation of extended-spectrum cephalosporins by CTX-M enzymes induced subtle changes in the active site and established a high density of electrostatic interactions. Interestingly, the product of the catalytic reaction initiates its own release because of steric hindrances and electrostatic repulsions. This suggests that there exists a general mechanism for product release for all members of the beta-lactamase family and probably for most carboxypeptidases.
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Affiliation(s)
- Julien Delmas
- CHU Clermont-Ferrand, Laboratoire de Bactériologie, Clermont-Ferrand F-63003, France
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34
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Toth M, Smith C, Frase H, Mobashery S, Vakulenko S. An antibiotic-resistance enzyme from a deep-sea bacterium. J Am Chem Soc 2010; 132:816-23. [PMID: 20000704 PMCID: PMC2826318 DOI: 10.1021/ja908850p] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe herein a highly proficient class A beta-lactamase OIH-1 from the bacterium Oceanobacillus iheyensis, whose habitat is the sediment at a depth of 1050 m in the Pacific Ocean. The OIH-1 structure was solved by molecular replacement and refined at 1.25 A resolution. OIH-1 has evolved to be an extremely halotolerant beta-lactamase capable of hydrolyzing its substrates in the presence of NaCl at saturating concentration. Not only is this the most highly halotolerant bacterial enzyme structure known to date, it is also the highest resolution halophilic protein structure yet determined. Evolution of OIH-1 in the salinity of the ocean has resulted in a molecular surface that is coated with acidic residues, a marked difference from beta-lactamases of terrestrial sources. OIH-1 is the first example of an antibiotic-resistance enzyme that has evolved in the depths of the ocean in isolation from clinical selection and gives us an extraordinary glimpse into protein evolution under extreme conditions. It represents evidence for the existence of a reservoir of antibiotic-resistance enzymes in nature among microbial populations from deep oceanic sources.
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Affiliation(s)
- Marta Toth
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Clyde Smith
- Stanford Synchrotron Radiation Lightsource, Stanford University, Menlo Park, CA 94025
| | - Hilary Frase
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
| | - Sergei Vakulenko
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
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