1
|
Penicillin-binding proteins (PBPs) determine antibiotic action in Langmuir monolayers as nanoarchitectonics mimetic membranes of methicillin-resistant Staphylococcus aureus. Colloids Surf B Biointerfaces 2022; 214:112447. [PMID: 35334310 DOI: 10.1016/j.colsurfb.2022.112447] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/02/2022] [Accepted: 03/03/2022] [Indexed: 01/15/2023]
Abstract
The membrane of methicillin-resistant Staphylococcus aureus (MRSA) contains penicillin-binding proteins (PBPs) in the phospholipidic bilayer, with the protein PBP2a being linked with the resistance mechanism. In this work we confirm the role of PBP2a with molecular-level information obtained with Langmuir monolayers as cell membrane models. The MRSA cell membrane was mimicked with a mixed monolayer of dipalmitoyl phosphatidyl glycerol (DPPG) and cardiolipin (CL), also incorporating PBP2a. The surface pressure-area isotherms and the Brewster angle microscopy (BAM) images for these mixed monolayers were significantly affected by the antibiotic meropenem, which is PBP2a inhibitor. The meropenem effects were associated with the presence of PBP2a, as they were absent in the Langmuir monolayers without PBP2a. The relevance of PBP2a was confirmed with results where the antibiotic methicillin, known to be unsuitable to kill MRSA, had the same effects on mixed DPPG/CL and DPPG/CL-PBP2a monolayers since it prevented PBP2a from incorporating in the monolayer. The biological implication of the findings presented here is that a successful antibiotic against MRSA should be able to interact with PBP2a, but in the membrane.
Collapse
|
2
|
Hall L, Donovan E, Araya M, Idowa E, Jiminez-Segovia I, Folck A, Wells CD, Kimble-Hill AC. Identification of Specific Lysines and Arginines That Mediate Angiomotin Membrane Association. ACS OMEGA 2019; 4:6726-6736. [PMID: 31179409 PMCID: PMC6547806 DOI: 10.1021/acsomega.9b00165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 03/28/2019] [Indexed: 05/17/2023]
Abstract
The family of Angiomotin (Amot) proteins regulate several biological pathways associated with cellular differentiation, proliferation, and migration. These adaptor proteins target proteins to the apical membrane, actin fibers, or the nucleus. A major function of the Amot coiled-coil homology (ACCH) domain is to initiate protein interactions with the cellular membrane, particularly those containing phosphatidylinositol lipids. The work presented in this article uses several ACCH domain lysine/arginine mutants to probe the relative importance of individual residues for lipid binding. This identified four lysine and three arginine residues that mediate full lipid binding. Based on these findings, three of these residues were mutated to glutamates in the Angiomotin 80 kDa splice form and were incorporated into human mammary cell lines. Results show that mutating three of these residues in the context of full-length Angiomotin reduced the residence of the protein at the apical membrane. These findings provide new insight into how the ACCH domain mediates lipid binding to enable Amot proteins to control epithelial cell growth.
Collapse
Affiliation(s)
- Le’Celia Hall
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| | - Emily Donovan
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| | - Michael Araya
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| | - Eniola Idowa
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| | - Ilse Jiminez-Segovia
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| | - Anthony Folck
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| | - Clark D. Wells
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| | - Ann C. Kimble-Hill
- Department of Biochemistry
and Molecular Biology, Indiana University
School of Medicine, Room MS 4053, 635 Barnhill Drive, Indianapolis, Indiana 46202, United
States
| |
Collapse
|
3
|
Peck C, Virtanen P, Johnson D, Kimble-Hill AC. Using the Predicted Structure of the Amot Coiled Coil Homology Domain to Understand Lipid Binding. INDIANA UNIVERSITY JOURNAL OF UNDERGRADUATE RESEARCH 2018; 4:27-46. [PMID: 30957019 PMCID: PMC6448796 DOI: 10.14434/iujur.v4i1.24528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiomotins (Amots) are a family of adapter proteins that modulate cellular polarity, differentiation, proliferation, and migration. Amot family members have a characteristic lipid-binding domain, the coiled coil homology (ACCH) domain that selectively targets the protein to membranes, which has been directly linked to its regulatory role in the cell. Several spot blot assays were used to validate the regions of the domain that participate in its membrane association, deformation, and vesicle fusion activity, which indicated the need for a structure to define the mechanism. Therefore, we sought to understand the structure-function relationship of this domain in order to find ways to modulate these signaling pathways. After many failed attempts to crystallize the ACCH domain of each Amot family member for structural analysis, we decided to pursue homologous models that could be refined using small angle x-ray scattering data. Theoretical models were produced using the homology software SWISS-MODEL and threading software I-TASSER and LOMETS, followed by comparison to SAXS data for model selection and refinement. We present a theoretical model of the domain that is driven by alpha helices and short random coil regions. These alpha helical regions form a classic dimer interface followed by two wide spread legs that we predict to be the lipid binding interface.
Collapse
|
4
|
Kimble-Hill AC, Petrache HI, Seifert S, Firestone MA. Reorganization of Ternary Lipid Mixtures of Nonphosphorylated Phosphatidylinositol Interacting with Angiomotin. J Phys Chem B 2018; 122:8404-8415. [PMID: 29877706 PMCID: PMC6351316 DOI: 10.1021/acs.jpcb.7b12641] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Phosphatidylinositol (PI) lipids are necessary for many cellular signaling pathways of membrane associated proteins, such as angiomotin (Amot). The Amot family regulates cellular polarity, growth, and migration. Given the low concentration of PI lipids in these membranes, it is likely that such protein-membrane interactions are stabilized by lipid domains or small lipid clusters. By small-angle X-ray scattering, we show that nonphosphorylated PI lipids induce lipid demixing in ternary mixtures of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), likely because of preferential interactions between the head groups of PE and PI. These results were obtained in the presence of buffer containing tris(hydroxymethyl)aminomethane, 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, NaCl, ethylenediaminetetraacetic acid, dithiothreitol, and benzamidine at pH 8.0 that in previous work showed an ability to cause PC to phase separate but are necessary to stabilize Amot for in vitro experimentation. Collectively, this provided a framework for determining the effect of Amot on lipid organization. Using fluorescence spectroscopy, we were able to show that the association of Amot with this lipid platform causes significant reorganization of the lipid into a more homogenous structure. This reorganization mechanism could be the basis for Amot membrane association and fusogenic activity previously described in the literature and should be taken into consideration in future protein-membrane interaction studies.
Collapse
Affiliation(s)
- Ann C. Kimble-Hill
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, MS 4053, 635 Barnhill Dr., Indianapolis, Indiana 46202, United States
| | - Horia I. Petrache
- Department of Physics, Indiana University Purdue University Indianapolis, LD 154, 402 N. Blackford Street, Indianapolis, Indiana 46202, United States
| | - Soenke Seifert
- X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Millicent A. Firestone
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, MPA-CINT, MS K771, Los Alamos, New Mexico 87545, United States
| |
Collapse
|
5
|
Srisuknimit V, Qiao Y, Schaefer K, Kahne D, Walker S. Peptidoglycan Cross-Linking Preferences of Staphylococcus aureus Penicillin-Binding Proteins Have Implications for Treating MRSA Infections. J Am Chem Soc 2017; 139:9791-9794. [PMID: 28691491 PMCID: PMC5613940 DOI: 10.1021/jacs.7b04881] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a global public health problem. MRSA strains have acquired a non-native penicillin-binding protein called PBP2a that cross-links peptidoglycan when the native S. aureus PBPs are inhibited by β-lactams. It has been proposed that the native S. aureus PBPs can use cell wall precursors having different glycine branch lengths (penta-, tri-, or monoglycine), while PBP2a can only cross-link peptidoglycan strands bearing a complete pentaglycine branch. This hypothesis has never been tested because the necessary substrates have not been available. Here, we compared the ability of PBP2a and two native S. aureus transpeptidases to cross-link peptidoglycan strands bearing different glycine branches. We show that purified PBP2a can cross-link glycan strands bearing penta- and triglycine, but not monoglycine, and experiments in cells provide support for these findings. Because PBP2a cannot cross-link peptidoglycan containing monoglycine, this study implicates the enzyme (FemA) that extends the monoglycine branch to triglycine on Lipid II as an ideal target for small molecules that restore sensitivity of MRSA to β-lactams.
Collapse
Affiliation(s)
- Veerasak Srisuknimit
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
| | - Yuan Qiao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02138, United States
| | - Kaitlin Schaefer
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02138, United States
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
| | - Suzanne Walker
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02138, United States
| |
Collapse
|
6
|
Ning Y, Gao Q, Zhang X, Wei K, Chen L. A Graphene Oxide-Based Sensing Platform for the Determination of Methicillin-Resistant Staphylococcus aureus Based on Strand-Displacement Polymerization Recycling and Synchronous Fluorescent Signal Amplification. ACTA ACUST UNITED AC 2016; 21:851-7. [PMID: 27286718 DOI: 10.1177/1087057116653564] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 05/16/2016] [Indexed: 11/16/2022]
Abstract
To develop new technology for detecting methicillin-resistant Staphylococcus aureus (MRSA), a novel fluorescent biosensor based on Klenow fragment (KF)-assisted target recycling amplification and synchronous fluorescence analysis was created. Carboxy-fluorescein (FAM)-labeled single-stranded DNA (ssDNA) containing a capture probe and a signal probe was adsorbed onto the surface of graphene oxide (GO) via π-stacking interactions, resulting in the fluorescence quenching of the dye. When target and primer were introduced, the fluorescence was restored due to P0 being completely released from the surface of the GO. Meanwhile, by using the KF and exploiting the synergistic effect of FAM and the double-stranded DNA (dsDNA)-SYBR Green I duplex structure, the fluorescence in this detection system was considerably amplified and the sensitivity was improved. The proposed strategy for mecA gene analysis showed a good linear range from 1 to 40 nmol/L, with a lower limit of detection of 0.5 nmol/L. In addition, a bacterial sample harboring the mecA gene was also detected, and its lower detection limit was up to 300 colony-forming units (CFU)/mL. Accordingly, this biosensor exhibits high sensitivity and selectivity and has great potential for early clinical diagnosis and treatment.
Collapse
Affiliation(s)
- Yi Ning
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, People's Republic of China
| | - Qiang Gao
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, People's Republic of China
| | - Xiaoqing Zhang
- Department of Inorganic Physical Chemistry, The Pharmacy School of Hunan University of Chinese Medicine, Changsha, Hunan, People's Republic of China
| | - Ke Wei
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, People's Republic of China
| | - Lingli Chen
- Department of Microbiology, The Medicine School of Hunan University of Chinese Medicine, Changsha, Hunan, People's Republic of China
| |
Collapse
|
7
|
Ba X, Harrison EM, Edwards GF, Holden MTG, Larsen AR, Petersen A, Skov RL, Peacock SJ, Parkhill J, Paterson GK, Holmes MA. Novel mutations in penicillin-binding protein genes in clinical Staphylococcus aureus isolates that are methicillin resistant on susceptibility testing, but lack the mec gene. J Antimicrob Chemother 2013; 69:594-7. [PMID: 24216768 PMCID: PMC3922151 DOI: 10.1093/jac/dkt418] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Objectives Methicillin-resistant Staphylococcus aureus (MRSA) is an important global health problem. MRSA resistance to β-lactam antibiotics is mediated by the mecA or mecC genes, which encode an alternative penicillin-binding protein (PBP) 2a that has a low affinity to β-lactam antibiotics. Detection of mec genes or PBP2a is regarded as the gold standard for the diagnosis of MRSA. We identified four MRSA isolates that lacked mecA or mecC genes, but were still phenotypically resistant to pencillinase-resistant β-lactam antibiotics. Methods The four human S. aureus isolates were investigated by whole genome sequencing and a range of phenotypic assays. Results We identified a number of amino acid substitutions present in the endogenous PBPs 1, 2 and 3 that were found in the resistant isolates but were absent in closely related susceptible isolates and which may be the basis of resistance. Of particular interest are three identical amino acid substitutions in PBPs 1, 2 and 3, occurring independently in isolates from at least two separate multilocus sequence types. Two different non-conservative substitutions were also present in the same amino acid of PBP1 in two isolates from two different sequence types. Conclusions This work suggests that phenotypically resistant MRSA could be misdiagnosed using molecular methods alone and provides evidence of alternative mechanisms for β-lactam resistance in MRSA that may need to be considered by diagnostic laboratories.
Collapse
Affiliation(s)
- Xiaoliang Ba
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Shapiro AB, Gu RF, Gao N, Livchak S, Thresher J. Continuous fluorescence anisotropy-based assay of BOCILLIN FL penicillin reaction with penicillin binding protein 3. Anal Biochem 2013; 439:37-43. [PMID: 23603065 DOI: 10.1016/j.ab.2013.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 03/12/2013] [Accepted: 04/01/2013] [Indexed: 10/27/2022]
Abstract
We report a simple, rapid, and reproducible fluorescence anisotropy-based method for measuring rate constants for acylation and deacylation of soluble penicillin binding protein (PBP) constructs by compounds in microtiter plates by means of competition with time-dependent acylation by BOCILLIN FL. The method is demonstrated by measuring the acylation rate constants of the PBP3 periplasmic domains from Pseudomonas aeruginosa and Acinetobacter baumannii by BOCILLIN FL, aztreonam, meropenem, and ceftazidime. The new method requires very little protein and can be completed in approximately 1h per compound. A set of BOCILLIN FL acylation progress curves collected over a range of competitor concentrations is fit globally to a kinetic model by numerical integration. First-order deacylation rate constants could also be measured, as demonstrated with a catalytically impaired mutant OXA-10 β-lactamase.
Collapse
Affiliation(s)
- Adam B Shapiro
- Bioscience Department, Infection Innovative Medicines, AstraZeneca R&D Boston, Waltham, MA 02451, USA.
| | | | | | | | | |
Collapse
|
9
|
Development of new drugs for an old target: the penicillin binding proteins. Molecules 2012; 17:12478-505. [PMID: 23095893 PMCID: PMC6268044 DOI: 10.3390/molecules171112478] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 10/05/2012] [Accepted: 10/17/2012] [Indexed: 11/16/2022] Open
Abstract
The widespread use of β-lactam antibiotics has led to the worldwide appearance of drug-resistant strains. Bacteria have developed resistance to β-lactams by two main mechanisms: the production of β-lactamases, sometimes accompanied by a decrease of outer membrane permeability, and the production of low-affinity, drug resistant Penicillin Binding Proteins (PBPs). PBPs remain attractive targets for developing new antibiotic agents because they catalyse the last steps of the biosynthesis of peptidoglycan, which is unique to bacteria, and lies outside the cytoplasmic membrane. Here we summarize the “current state of the art” of non-β-lactam inhibitors of PBPs, which have being developed in an attempt to counter the emergence of β-lactam resistance. These molecules are not susceptible to hydrolysis by β-lactamases and thus present a real alternative to β-lactams. We present transition state analogs such as boronic acids, which can covalently bind to the active serine residue in the catalytic site. Molecules containing ring structures different from the β-lactam-ring like lactivicin are able to acylate the active serine residue. High throughput screening methods, in combination with virtual screening methods and structure based design, have allowed the development of new molecules. Some of these novel inhibitors are active against major pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and thus open avenues new for the discovery of novel antibiotics.
Collapse
|
10
|
Dzhekieva L, Kumar I, Pratt RF. Inhibition of Bacterial DD-Peptidases (Penicillin-Binding Proteins) in Membranes and in Vivo by Peptidoglycan-Mimetic Boronic Acids. Biochemistry 2012; 51:2804-11. [DOI: 10.1021/bi300148v] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Liudmila Dzhekieva
- Department of Chemistry, Wesleyan University, Lawn Avenue, Middletown, Connecticut 06459,
United
States
| | - Ish Kumar
- School of Natural
Sciences, Fairleigh Dickinson University, Teaneck, New Jersey 07666, United States
| | - R. F. Pratt
- Department of Chemistry, Wesleyan University, Lawn Avenue, Middletown, Connecticut 06459,
United
States
| |
Collapse
|