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Hintzen JCJ, Abujubara H, Tietze D, Tietze AA. The Complete Assessment of Small Molecule and Peptidomimetic Inhibitors of Sortase A Towards Antivirulence Treatment. Chemistry 2024; 30:e202401103. [PMID: 38716707 DOI: 10.1002/chem.202401103] [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: 03/19/2024] [Indexed: 06/20/2024]
Abstract
This review covers the most recent advances in the development of inhibitors for the bacterial enzyme sortase A (SrtA). Sortase A (SrtA) is a critical virulence factor, present ubiquitously in Gram-positive bacteria of which many are pathogenic. Sortases are key enzymes regulating bacterial adherence to host cells, by anchoring extracellular matrix-binding proteins to the bacterial outer cell wall. By targeting virulence factors, effective treatment can be achieved, without inducing antibiotic resistance to the treatment. This is a potentially more sustainable, long-term approach to treating bacterial infections, including ones that display multiple resistance to current therapeutics. There are many promising approaches available for SrtA inhibition, some of which have the potential to advance into further clinical development, with peptidomimetic and in vivo active small molecules being among the most promising. There are currently no approved drugs on the market targeting SrtA, despite its promise, adding to the relevance of this review article, as it extends to the pharmaceutical industry additionally to academic researchers.
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Affiliation(s)
- Jordi C J Hintzen
- University of Gothenburg, Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, Kemigården 4, 412 96, Göteborg, Sweden
| | - Helal Abujubara
- University of Gothenburg, Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, Kemigården 4, 412 96, Göteborg, Sweden
| | - Daniel Tietze
- University of Gothenburg, Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, Kemigården 4, 412 96, Göteborg, Sweden
| | - Alesia A Tietze
- University of Gothenburg, Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, Kemigården 4, 412 96, Göteborg, Sweden
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2
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Mahmood Janlou MA, Sahebjamee H, Yazdani M, Fozouni L. Structure-based virtual screening and molecular dynamics approaches to identify new inhibitors of Staphylococcus aureus sortase A. J Biomol Struct Dyn 2024; 42:1157-1169. [PMID: 37184111 DOI: 10.1080/07391102.2023.2201863] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 03/28/2023] [Indexed: 05/16/2023]
Abstract
Staphylococcus aureus is a prevalent Gram-positive bacteria leading cause of a wide range of human pathologies. Moreover, antibiotic résistance of pathogenesis bacteria is one of the worldwide health problems. In Gram-positive bacteria, the enzyme of SrtA, is responsible for the anchoring of surface-exposed proteins to the cell wall peptidoglycan. Because of its critical role in Gram-positive bacterial pathogenesis, SrtA is an attractive target for anti-virulence during drug development. To date, some SrtA inhibitors have been discovered most of them being derived from flavonoid compounds, like Myricetin. In order to provide potential hit molecules against SrtA for clinical use, we obtained a total of 293 compounds by performing in silico shape-based screening of compound libraries against Myristin as a reference structure. Employing molecular docking and scoring functions, the top 3 compounds Apigenin, Efloxate, and Compound 8261032 were screened by comparing their docking scores with Myricetin. Furthermore, MD simulations and MM-PBSA binding energy calculation studies revealed that only Compound 8261032 strongly binds to the catalytic core of the SrtA enzyme than Myricetin, and stable behavior was consistently observed in the docking complex. Compound 8261032 showed a good number of hydrogen bonds with SrtA and higher MM-PBSA binding energy when compared to all three molecules. Also, it makes strength interactions with Arg139 and His62, which are critical for SrtA biological activity. This study showed that the development of this inhibitor could be a fundamental strategy against resistant bacteria, but further studies in vitro are needed to confirm this claim.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Mehr Ali Mahmood Janlou
- Department of Biophysics, Faculty of Biological Sciences, Gorgan Branch, Islamic Azad University, Gorgan, Iran
| | - Hassan Sahebjamee
- Department of Biophysics, Faculty of Biological Science, Varamin-Pishva Branch, Islamic Azad University, Varamin, Iran
| | - Mohsen Yazdani
- Laboratory of Bioinformatics and Drug Design, Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Leila Fozouni
- Department of Microbiology, Faculty of Biological Sciences, Gorgan Branch, Islamic Azad University, Gorgan, Iran
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3
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Abujubara H, Hintzen JCJ, Rahimi S, Mijakovic I, Tietze D, Tietze AA. Substrate-derived Sortase A inhibitors: targeting an essential virulence factor of Gram-positive pathogenic bacteria. Chem Sci 2023; 14:6975-6985. [PMID: 37389257 PMCID: PMC10306101 DOI: 10.1039/d3sc01209c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/30/2023] [Indexed: 07/01/2023] Open
Abstract
The bacterial transpeptidase Sortase A (SrtA) is a surface enzyme of Gram-positive pathogenic bacteria. It has been shown to be an essential virulence factor for the establishment of various bacterial infections, including septic arthritis. However, the development of potent Sortase A inhibitors remains an unmet challenge. Sortase A relies on a five amino acid sorting signal (LPXTG), by which it recognizes its natural target. We report the synthesis of a series of peptidomimetic inhibitors of Sortase A based on the sorting signal, supported by computational binding analysis. By employing a FRET-compatible substrate, our inhibitors were assayed in vitro. Among our panel, we identified several promising inhibitors with IC50 values below 200 μM, with our strongest inhibitor - LPRDSar - having an IC50 of 18.9 μM. Furthermore, it was discovered that three of our compounds show an effect on growth and biofilm inhibition of pathogenic Staphylococcus aureus, with the inclusion of a phenyl ring seemingly key to this effect. The most promising compound in our panel, BzLPRDSar, could inhibit biofilm formation at concentrations as low as 32 μg mL-1, manifesting it as a potential future drug lead. This could lead to treatments for MRSA infections in clinics and diseases such as septic arthritis, which has been directly linked with SrtA.
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Affiliation(s)
- Helal Abujubara
- Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg Kemigården 4 412 96 Göteborg Sweden
| | - Jordi C J Hintzen
- Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg Kemigården 4 412 96 Göteborg Sweden
| | - Shadi Rahimi
- Division of Systems & Synthetic Biology, Department of Biology and Biological Engineering, Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
| | - Ivan Mijakovic
- Division of Systems & Synthetic Biology, Department of Biology and Biological Engineering, Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
- The Novo Nordisk Foundation, Center for Biosustainability, Technical University of Denmark DK-2800 Kongens Lyngby Denmark
| | - Daniel Tietze
- Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg Kemigården 4 412 96 Göteborg Sweden
| | - Alesia A Tietze
- Department of Chemistry and Molecular Biology, Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg Kemigården 4 412 96 Göteborg Sweden
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Shulga DA, Kudryavtsev KV. Theoretical Studies of Leu-Pro-Arg-Asp-Ala Pentapeptide (LPRDA) Binding to Sortase A of Staphylococcus aureus. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238182. [PMID: 36500275 PMCID: PMC9890316 DOI: 10.3390/molecules27238182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/15/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
Abstract
Sortase A (SrtA) of Staphylococcus aureus is a well-defined molecular target to combat the virulence of these clinically important bacteria. However up to now no efficient drugs or even clinical candidates are known, hence the search for such drugs is still relevant and necessary. SrtA is a complex target, so many straight-forward techniques for modeling using the structure-based drug design (SBDD) fail to produce the results they used to bring for other, simpler, targets. In this work we conduct theoretical studies of the binding/activity of Leu-Pro-Arg-Asp-Ala (LPRDA) polypeptide, which was recently shown to possess antivirulence activity against S. aureus. Our investigation was aimed at establishing a framework for the estimation of the key interactions and subsequent modification of LPRDA, targeted at non-peptide molecules, with better drug-like properties than the original polypeptide. Firstly, the available PDB structures are critically analyzed and the criteria to evaluate the quality of the ligand-SrtA complex geometry are proposed. Secondly, the docking protocol was investigated to establish its applicability to the LPRDA-SrtA complex prediction. Thirdly, the molecular dynamics studies were carried out to refine the geometries and estimate the stability of the complexes, predicted by docking. The main finding is that the previously reported partially chaotic movement of the β6/β7 and β7/β8 loops of SrtA (being the intrinsically disordered parts related to the SrtA binding site) is exaggerated when SrtA is complexed with LPRDA, which in turn reveals all the signs of the flexible and structurally disordered molecule. As a result, a wealth of plausible LPRDA-SrtA complex conformations are hard to distinguish using simple modeling means, such as docking. The use of more elaborate modeling approaches may help to model the system reliably but at the cost of computational efficiency.
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Affiliation(s)
- Dmitry A. Shulga
- Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, 119991 Moscow, Russia
- Correspondence: (D.A.S.); (K.V.K.)
| | - Konstantin V. Kudryavtsev
- Laboratory of Molecular Pharmacology, Pirogov Russian National Research Medical University, Ostrovityanova Street 1, 117997 Moscow, Russia
- Correspondence: (D.A.S.); (K.V.K.)
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5
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Mangal P, Jha RK, Jain M, Singh AK, Muthukumaran J. Identification and prioritization of promising lead molecules from Syzygium aromaticum against Sortase C from Streptococcus pyogenes: an in silico investigation. J Biomol Struct Dyn 2022:1-18. [PMID: 35706070 DOI: 10.1080/07391102.2022.2086921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Sortases are extracellular transpeptidases that play an essential role in the adhesion of secreted proteins to the peptidoglycan layer of the cell wall of Gram-negative bacteria. Sortases are an important drug target protein due to their involvement in synthesizing the peptidoglycan cell wall of Streptococcus pyogenes, and these are not found in Homo sapiens. In this study, initially, we have performed protein sequence analysis to understand the sequential properties of Sortase C. Next, a comparative protein modeling approach was used to predict the three-dimensional model of Sortase C based on the crystal structure of Sortase C from Streptococcus pneumoniae. Virtual screening with an in-house library of phytochemicals from Syzygium aromaticum and molecular docking studies were performed to identify the promising lead molecules. These compounds were also analyzed for their drug-like and pharmacokinetic properties. Subsequently, the protein-ligand complexes of the selected ligands were subjected to molecular dynamics (MD) simulations to investigate their dynamic behavior in physiological conditions. The global and essential dynamics analyses result implied that the Sortase C complexes of the proposed three lead candidates exhibited adequate stability during the MD simulations. Additionally, the three proposed molecules showed favorable MM/PBSA binding free energy values ranging from -13.8 +/- 9.41 to -56.6 +/- 8.82 kcal/mol. After an extensive computational investigation, we have identified three promising lead candidates (CID:13888122, CID:3694932 and CID:102445430) against Sortase C from S. pyogenes. The result obtained from these computational studies can be used to screen and develop the inhibitors against Sortase C from S. pyogenes. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Purti Mangal
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
| | - Rajat Kumar Jha
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
| | - Monika Jain
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
| | - Amit Kumar Singh
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
| | - Jayaraman Muthukumaran
- Department of Biotechnology, School of Engineering and Technology, Sharda University, Greater Noida, India
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Gao M, Johnson DA, Piper IM, Kodama HM, Svendsen JE, Tahti E, Longshore‐Neate F, Vogel B, Antos JM, Amacher JF. Structural and biochemical analyses of selectivity determinants in chimeric Streptococcus Class A sortase enzymes. Protein Sci 2022; 31:701-715. [PMID: 34939250 PMCID: PMC8862441 DOI: 10.1002/pro.4266] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 01/22/2023]
Abstract
Sequence variation in related proteins is an important characteristic that modulates activity and selectivity. An example of a protein family with a large degree of sequence variation is that of bacterial sortases, which are cysteine transpeptidases on the surface of gram-positive bacteria. Class A sortases are responsible for attachment of diverse proteins to the cell wall to facilitate environmental adaption and interaction. These enzymes are also used in protein engineering applications for sortase-mediated ligations (SML) or sortagging of protein targets. We previously investigated SrtA from Streptococcus pneumoniae, identifying a number of putative β7-β8 loop-mediated interactions that affected in vitro enzyme function. We identified residues that contributed to the ability of S. pneumoniae SrtA to recognize several amino acids at the P1' position of the substrate motif, underlined in LPXTG, in contrast to the strict P1' Gly recognition of SrtA from Staphylococcus aureus. However, motivated by the lack of a structural model for the active, monomeric form of S. pneumoniae SrtA, here, we expanded our studies to other Streptococcus SrtA proteins. We solved the first monomeric structure of S. agalactiae SrtA which includes the C-terminus, and three others of β7-β8 loop chimeras from S. pyogenes and S. agalactiae SrtA. These structures and accompanying biochemical data support our previously identified β7-β8 loop-mediated interactions and provide additional insight into their role in Class A sortase substrate selectivity. A greater understanding of individual SrtA sequence and structural determinants of target selectivity may also facilitate the design or discovery of improved sortagging tools.
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Affiliation(s)
- Melody Gao
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - D. Alex Johnson
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Isabel M. Piper
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Hanna M. Kodama
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Justin E. Svendsen
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Elise Tahti
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | | | - Brandon Vogel
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - John M. Antos
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Jeanine F. Amacher
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
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7
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Barthels F, Meyr J, Hammerschmidt SJ, Marciniak T, Räder HJ, Ziebuhr W, Engels B, Schirmeister T. 2-Sulfonylpyrimidines as Privileged Warheads for the Development of S. aureus Sortase A Inhibitors. Front Mol Biosci 2022; 8:804970. [PMID: 35047562 PMCID: PMC8763382 DOI: 10.3389/fmolb.2021.804970] [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: 10/29/2021] [Accepted: 12/03/2021] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus is one of the most frequent causes of nosocomial and community-acquired infections, with emerging multiresistant isolates causing a significant burden to public health systems. We identified 2-sulfonylpyrimidines as a new class of potent inhibitors against S. aureus sortase A acting by covalent modification of the active site cysteine 184. Series of derivatives were synthesized to derive structure-activity relationship (SAR) with the most potent compounds displaying low micromolar KI values. Studies on the inhibition selectivity of homologous cysteine proteases showed that 2-sulfonylpyrimidines reacted efficiently with protonated cysteine residues as found in sortase A, though surprisingly, no reaction occurred with the more nucleophilic cysteine residue from imidazolinium-thiolate dyads of cathepsin-like proteases. By means of enzymatic and chemical kinetics as well as quantum chemical calculations, it could be rationalized that the SNAr reaction between protonated cysteine residues and 2-sulfonylpyrimidines proceeds in a concerted fashion, and the mechanism involves a ternary transition state with a conjugated base. Molecular docking and enzyme inhibition at variable pH values allowed us to hypothesize that in sortase A this base is represented by the catalytic histidine 120, which could be substantiated by QM model calculation with 4-methylimidazole as histidine analog.
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Affiliation(s)
- Fabian Barthels
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University, Mainz, Germany
| | - Jessica Meyr
- Institute of Physical and Theoretical Chemistry, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Stefan J Hammerschmidt
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University, Mainz, Germany
| | - Tessa Marciniak
- Institute for Molecular Infection Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | | | - Wilma Ziebuhr
- Institute for Molecular Infection Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Bernd Engels
- Institute of Physical and Theoretical Chemistry, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Tanja Schirmeister
- Institute for Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-University, Mainz, Germany
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Selection of Promising Novel Fragment Sized S. aureus SrtA Noncovalent Inhibitors Based on QSAR and Docking Modeling Studies. Molecules 2021; 26:molecules26247677. [PMID: 34946760 PMCID: PMC8709105 DOI: 10.3390/molecules26247677] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 11/22/2022] Open
Abstract
Sortase A (SrtA) of Staphylococcus aureus has been identified as a promising target to a new type of antivirulent drugs, and therefore, the design of lead molecules with a low nanomolar range of activity and suitable drug-like properties is important. In this work, we aimed at identifying new fragment-sized starting points to design new noncovalent S. aureus SrtA inhibitors by making use of the dedicated molecular motif, 5-arylpyrrolidine-2-carboxylate, which has been previously shown to be significant for covalent binding SrtA inhibitors. To this end, an in silico approach combining QSAR and molecular docking studies was used. The known SrtA inhibitors from the ChEMBL database with diverse scaffolds were first employed to derive descriptors and interpret their significance and correlation to activity. Then, the classification and regression QSAR models were built, which were used for rough ranking of the virtual library of the synthetically feasible compounds containing the dedicated motif. Additionally, the virtual library compounds were docked into the “activated” model of SrtA (PDB:2KID). The consensus ranking of the virtual library resulted in the most promising structures, which will be subject to further synthesis and experimental testing in order to establish new fragment-like molecules for further development into antivirulent drugs.
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9
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Sapra R, Rajora AK, Kumar P, Maurya GP, Pant N, Haridas V. Chemical Biology of Sortase A Inhibition: A Gateway to Anti-infective Therapeutic Agents. J Med Chem 2021; 64:13097-13130. [PMID: 34516107 DOI: 10.1021/acs.jmedchem.1c00386] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is the leading cause of hospital-acquired infections. The enzyme sortase A, present on the cell surface of S. aureus, plays a key role in bacterial virulence without affecting the bacterial viability. Inhibition of sortase A activity offers a powerful but clinically less explored therapeutic strategy, as it offers the possibility of not inducing any selective pressure on the bacteria to evolve drug-resistant strains. In this Perspective, we offer a chemical space narrative for the design of sortase A inhibitors, as delineated into three broad domains: peptidomimetics, natural products, and synthetic small molecules. This provides immense opportunities for medicinal chemists to alleviate the ever-growing crisis of antibiotic resistance.
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Affiliation(s)
- Rachit Sapra
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Amit K Rajora
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Pushpendra Kumar
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Govind P Maurya
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - Nalin Pant
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
| | - V Haridas
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi-110016, India
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10
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Nitulescu G, Margina D, Zanfirescu A, Olaru OT, Nitulescu GM. Targeting Bacterial Sortases in Search of Anti-Virulence Therapies with Low Risk of Resistance Development. Pharmaceuticals (Basel) 2021; 14:ph14050415. [PMID: 33946434 PMCID: PMC8147154 DOI: 10.3390/ph14050415] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 12/29/2022] Open
Abstract
Increasingly ineffective antibiotics and rapid spread of multi- and pan-resistant bacteria represent a global health threat; hence, the need of developing new antimicrobial medicines. A first step in this direction is identifying new molecular targets, such as virulence factors. Sortase A represents a virulence factor essential for the pathogenesis of Gram-positive pathogens, some of which have a high risk for human health. We present here an exhaustive collection of sortases inhibitors grouped by relevant chemical features: vinyl sulfones, 3-aryl acrylic acids and derivatives, flavonoids, naphtoquinones, anthraquinones, indoles, pyrrolomycins, isoquinoline derivatives, aryl β-aminoethyl ketones, pyrazolethiones, pyridazinones, benzisothiazolinones, 2-phenyl-benzoxazole and 2-phenyl-benzofuran derivatives, thiadiazoles, triazolothiadiazoles, 2-(2-phenylhydrazinylidene)alkanoic acids, and 1,2,4-thiadiazolidine-3,5-dione. This review focuses on highlighting their structure–activity relationships, using the half maximal inhibitory concentration (IC50), when available, as an indicator of each compound effect on a specific sortase. The information herein is useful for acquiring knowledge on diverse natural and synthetic sortases inhibitors scaffolds and for understanding the way their structural variations impact IC50. It will hopefully be the inspiration for designing novel effective and safe sortase inhibitors in order to create new anti-infective compounds and to help overcoming the current worldwide antibiotic shortage.
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11
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Design and Synthesis of Small Molecules as Potent Staphylococcus aureus Sortase A Inhibitors. Antibiotics (Basel) 2020; 9:antibiotics9100706. [PMID: 33081148 PMCID: PMC7602840 DOI: 10.3390/antibiotics9100706] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 01/25/2023] Open
Abstract
The widespread and uncontrollable emergence of antibiotic-resistant bacteria, especially methicillin-resistant Staphylococcus aureus, has promoted a wave of efforts to discover a new generation of antibiotics that prevent or treat bacterial infections neither as bactericides nor bacteriostats. Due to its crucial role in virulence and its nonessentiality in bacterial survival, sortase A has been considered as a great target for new antibiotics. Sortase A inhibitors have emerged as promising alternative antivirulence agents against bacteria. Herein, the structural and preparative aspects of some small synthetic organic compounds that block the pathogenic action of sortase A have been described.
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12
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Sharma G, Deuis JR, Jia X, Mueller A, Vetter I, Mobli M. Recombinant production, bioconjugation and membrane binding studies ofPn3a, a selective Na V1.7 inhibitor. Biochem Pharmacol 2020; 181:114148. [PMID: 32663452 DOI: 10.1016/j.bcp.2020.114148] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/19/2020] [Accepted: 07/08/2020] [Indexed: 11/28/2022]
Abstract
Chronic pain is a common and often debilitating condition. Existing treatments are either inefficacious or associated with a wide range of side effects. The progress on developing safer and more effective analgesics has been slow, in large part due to our limited understanding of the physiological mechanisms underlying pain in different diseases. Generation and propagation of action potentials is a central component of pain sensation and voltage-gated sodium channels (NaVs) play a critical role in this process. In particular, the NaV subtype 1.7, has emerged as a promising universal target for the treatment of pain. Recently, a spider venom peptide, μ-TRTX-Pn3a, was found to be a highly selective inhibitor of NaV1.7. Here, we report the first recombinant expression method for Pn3a in a bacterial host, which provides an inexpensive route to production. Furthermore, we have developed a method for bio-conjugation of our recombinantly produced Pn3a via sortase A-mediated ligation, providing avenues for further pre-clinical development. We demonstrate how heterologous expression in bacteria enables facile isotope labelling of Pn3a, which allowed us to study the membrane binding properties of the peptide by high-resolution solution-state nuclear magnetic resonance (NMR) spectroscopy using a recently developed lipid nanodisc system. The heteronuclear NMR data indicate that the C-terminal region of the peptide undergoes a conformational change upon lipid binding. The membrane binding properties of Pn3a are further validated using isothermal titration calorimetry (ITC), which revealed that Pn3a binds to zwitterionic planar lipid bilayers with thermodynamics that are largely driven by enthalpic contributions.
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Affiliation(s)
- Gagan Sharma
- Centre for Advanced Imaging, The University of Queensland, Australia.
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, Australia.
| | - Xinying Jia
- Centre for Advanced Imaging, The University of Queensland, Australia.
| | - Alexander Mueller
- Institute for Molecular Bioscience, The University of Queensland, Australia.
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, Australia; School of Pharmacy, The University of Queensland, Australia.
| | - Mehdi Mobli
- Centre for Advanced Imaging, The University of Queensland, Australia.
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13
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Barthels F, Marincola G, Marciniak T, Konhäuser M, Hammerschmidt S, Bierlmeier J, Distler U, Wich PR, Tenzer S, Schwarzer D, Ziebuhr W, Schirmeister T. Asymmetric Disulfanylbenzamides as Irreversible and Selective Inhibitors of Staphylococcus aureus Sortase A. ChemMedChem 2020; 15:839-850. [PMID: 32118357 PMCID: PMC7318353 DOI: 10.1002/cmdc.201900687] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/07/2020] [Indexed: 12/19/2022]
Abstract
Staphylococcus aureus is one of the most frequent causes of nosocomial and community-acquired infections, with drug-resistant strains being responsible for tens of thousands of deaths per year. S. aureus sortase A inhibitors are designed to interfere with virulence determinants. We have identified disulfanylbenzamides as a new class of potent inhibitors against sortase A that act by covalent modification of the active-site cysteine. A broad series of derivatives were synthesized to derive structure-activity relationships (SAR). In vitro and in silico methods allowed the experimentally observed binding affinities and selectivities to be rationalized. The most active compounds were found to have single-digit micromolar Ki values and caused up to a 66 % reduction of S. aureus fibrinogen attachment at an effective inhibitor concentration of 10 μM. This new molecule class exhibited minimal cytotoxicity, low bacterial growth inhibition and impaired sortase-mediated adherence of S. aureus cells.
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Affiliation(s)
- Fabian Barthels
- Institute for Pharmacy and BiochemistryJohannes-Gutenberg-University of MainzStaudinger Weg 555128MainzGermany
| | - Gabriella Marincola
- Institute for Molecular Infection BiologyJulius-Maximilians-University of WürzburgJosef-Schneider-Strasse 297080WürzburgGermany
| | - Tessa Marciniak
- Institute for Molecular Infection BiologyJulius-Maximilians-University of WürzburgJosef-Schneider-Strasse 297080WürzburgGermany
| | - Matthias Konhäuser
- Institute for Pharmacy and BiochemistryJohannes-Gutenberg-University of MainzStaudinger Weg 555128MainzGermany
| | - Stefan Hammerschmidt
- Institute for Pharmacy and BiochemistryJohannes-Gutenberg-University of MainzStaudinger Weg 555128MainzGermany
| | - Jan Bierlmeier
- Interfaculty Institute of BiochemistryEberhard-Karls-University of TübingenHoppe-Seyler-Strasse 472076TübingenGermany
| | - Ute Distler
- Institute for ImmunologyUniversity Medical CenterJohannes-Gutenberg-University of MainzLangenbeckstr. 155131MainzGermany
- Focus Program Translational Neuroscience (FTN)University Medical CenterLangenbeckstr. 155131MainzGermany
| | - Peter R. Wich
- Institute for Pharmacy and BiochemistryJohannes-Gutenberg-University of MainzStaudinger Weg 555128MainzGermany
- School of Chemical EngineeringUniversity of New South WalesScience and Engineering BuildingSydneyNSW 2052Australia
| | - Stefan Tenzer
- Institute for ImmunologyUniversity Medical CenterJohannes-Gutenberg-University of MainzLangenbeckstr. 155131MainzGermany
| | - Dirk Schwarzer
- Interfaculty Institute of BiochemistryEberhard-Karls-University of TübingenHoppe-Seyler-Strasse 472076TübingenGermany
| | - Wilma Ziebuhr
- Institute for Molecular Infection BiologyJulius-Maximilians-University of WürzburgJosef-Schneider-Strasse 297080WürzburgGermany
| | - Tanja Schirmeister
- Institute for Pharmacy and BiochemistryJohannes-Gutenberg-University of MainzStaudinger Weg 555128MainzGermany
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14
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Ahuja LG, Taylor SS, Kornev AP. Tuning the "violin" of protein kinases: The role of dynamics-based allostery. IUBMB Life 2019; 71:685-696. [PMID: 31063633 PMCID: PMC6690483 DOI: 10.1002/iub.2057] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/12/2019] [Indexed: 12/17/2022]
Abstract
The intricacies of allosteric regulation of protein kinases continue to engage the research community. Allostery, or control from a distance, is seen as a fundamental biomolecular mechanism for proteins. From the traditional methods of conformational selection and induced fit, the field has grown to include the role of protein motions in defining a dynamics-based allosteric approach. Harnessing of these continuous motions in the protein to exert allosteric effects can be defined by a "violin" model that focuses on distributions of protein vibrations as opposed to concerted pathways. According to this model, binding of an allosteric modifier causes global redistribution of dynamics in the protein kinase domain that leads to changes in its catalytic properties. This model is consistent with the "entropy-driven allostery" mechanism proposed by Cooper and Dryden in 1984 and does not require, but does not exclude, any major structural changes. We provide an overview of practical implementation of the violin model and how it stands amidst the other known models of protein allostery. Protein kinases have been described as the biomolecules of interest. © 2019 IUBMB Life, 71(6):685-696, 2019.
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Affiliation(s)
- Lalima G. Ahuja
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA
| | - Susan S. Taylor
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA, USA
| | - Alexandr P. Kornev
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA
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15
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Wang X, Chen JL, Otting G, Su XC. Conversion of an amide to a high-energy thioester by Staphylococcus aureus sortase A is powered by variable binding affinity for calcium. Sci Rep 2018; 8:16371. [PMID: 30401805 PMCID: PMC6219580 DOI: 10.1038/s41598-018-34752-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 10/25/2018] [Indexed: 12/21/2022] Open
Abstract
Thioesters are key intermediates in biology, which often are generated from less energy-rich amide precursors. Staphylococcus aureus sortase A (SrtA) is an enzyme widely used in biotechnology for peptide ligation. The reaction proceeds in two steps, where the first step involves the conversion of an amide bond of substrate peptide into a thioester intermediate with the enzyme. Here we show that the free energy required for this step is matched by an about 30-fold increase in binding affinity of a calcium ion at the calcium binding site of SrtA, which is remote from the thioester bond. The magnitude of this allosteric effect highlights the importance of calcium for the activity of SrtA. The increase in calcium binding affinity upon binding of substrate not only achieves catalytic formation of an energy-rich intermediate in the absence of nucleotide triphosphates or any tight non-covalent enzyme-substrate interactions, but is also accompanied by accumulation of the labile thioester intermediate, which makes it directly observable in nuclear magnetic resonance (NMR) spectra.
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Affiliation(s)
- Xiao Wang
- State Key Laboratory of Elemento-Organic Chemistry, Department of Chemical Biology, College of Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, China
| | - Jia-Liang Chen
- State Key Laboratory of Elemento-Organic Chemistry, Department of Chemical Biology, College of Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, China
| | - Gottfried Otting
- Research School of Chemistry, Australian National University, Canberra, ACT, 2601, Australia
| | - Xun-Cheng Su
- State Key Laboratory of Elemento-Organic Chemistry, Department of Chemical Biology, College of Chemistry and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Nankai University, Tianjin, 300071, China.
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16
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Ca2+ binding induced sequential allosteric activation of sortase A: An example for ion-triggered conformational selection. PLoS One 2018; 13:e0205057. [PMID: 30321208 PMCID: PMC6188747 DOI: 10.1371/journal.pone.0205057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 09/19/2018] [Indexed: 12/11/2022] Open
Abstract
The allosteric activation of the intrinsically disordered enzyme Staphylococcus aureus sortase A is initiated via binding of a Ca2+ ion. Although Ca2+ binding was shown to initiate structural changes inducing disorder-to-order transitions, the details of the allosteric activation mechanism remain elusive. We performed long-term molecular dynamics simulations of sortase A without (3 simulations of 1.6 μs) and with bound Ca2+ (simulations of 1.6 μs, 1.8 μs, and 2.5 μs). Our results show that Ca2+ binding causes not only ordering of the disordered β6/β7 loop of the protein, but also modulates hinge motions in the dynamic β7/β8 loop, which is important for the catalytic activity of the enzyme. Cation binding triggers signal transmission from the Ca2+ binding site to the dynamic β7/β8 loop via the repetitive folding/unfolding of short helical stretches of the disordered β6/β7 loop. These correlated structural rearrangements lead to several distinct conformational states of the binding groove, which show optimal binding features for the sorting signal motif and feature binding energies up to 20 kcal/mol more favorable than observed for the sortase A without Ca2+. The presented results indicate a highly correlated, conformational selection-based activation mechanism of the enzyme triggered by cation binding. They also demonstrate the importance of the dynamics of intrinsically disordered regions for allosteric regulation.
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17
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Self-organization, entropy and allostery. Biochem Soc Trans 2018; 46:587-597. [PMID: 29678954 DOI: 10.1042/bst20160144] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 03/14/2018] [Accepted: 03/19/2018] [Indexed: 12/12/2022]
Abstract
Allostery is a fundamental regulatory mechanism in biology. Although generally accepted that it is a dynamics-driven process, the exact molecular mechanism of allosteric signal transmission is hotly debated. We argue that allostery is as a part of a bigger picture that also includes fractal-like properties of protein interior, hierarchical protein folding and entropy-driven molecular recognition. Although so far all these phenomena were studied separately, they stem from the same common root: self-organization of polypeptide chains and, thus, has to be studied collectively. This merge will allow the cross-referencing of a broad spectrum of multi-disciplinary data facilitating progress in all these fields.
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18
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Zheng M, Zhao J, Cui C, Fu Z, Li X, Liu X, Ding X, Tan X, Li F, Luo X, Chen K, Jiang H. Computational chemical biology and drug design: Facilitating protein structure, function, and modulation studies. Med Res Rev 2018; 38:914-950. [DOI: 10.1002/med.21483] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Mingyue Zheng
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Jihui Zhao
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Chen Cui
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Zunyun Fu
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Xutong Li
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Xiaohong Liu
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
- School of Life Science and Technology; ShanghaiTech University; Shanghai China
| | - Xiaoyu Ding
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Xiaoqin Tan
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Fei Li
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
- Department of Chemistry, College of Sciences; Shanghai University; Shanghai China
| | - Xiaomin Luo
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
| | - Kaixian Chen
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
- School of Life Science and Technology; ShanghaiTech University; Shanghai China
| | - Hualiang Jiang
- State Key Laboratory of Drug Research, Drug Discovery and Design Center, Shanghai Institute of Materia Medica; Chinese Academy of Sciences; Shanghai China
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19
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Nikghalb KD, Horvath NM, Prelesnik JL, Banks OGB, Filipov PA, Row RD, Roark TJ, Antos JM. Expanding the Scope of Sortase-Mediated Ligations by Using Sortase Homologues. Chembiochem 2017; 19:185-195. [PMID: 29124839 DOI: 10.1002/cbic.201700517] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Indexed: 02/04/2023]
Abstract
Sortase-catalyzed transacylation reactions are widely used for the construction of non-natural protein derivatives. However, the most commonly used enzyme for these strategies (sortase A from Staphylococcus aureus) is limited by its narrow substrate scope. To expand the range of substrates compatible with sortase-mediated reactions, we characterized the in vitro substrate preferences of eight sortase A homologues. From these studies, we identified sortase A enzymes that recognize multiple substrates that are unreactive toward sortase A from S. aureus. We further exploited the ability of sortase A from Streptococcus pneumoniae to recognize an LPATS substrate to perform a site-specific modification of the N-terminal serine residue in the naturally occurring antimicrobial peptide DCD-1L. Finally, we unexpectedly observed that certain substrates (LPATXG, X=Nle, Leu, Phe, Tyr) were susceptible to transacylation at alternative sites within the substrate motif, and sortase A from S. pneumoniae was capable of forming oligomers. Overall, this work provides a foundation for the further development of sortase enzymes for use in protein modification.
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Affiliation(s)
- Keyvan D Nikghalb
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
| | - Nicholas M Horvath
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
| | - Jesse L Prelesnik
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
| | - Orion G B Banks
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
| | - Pavel A Filipov
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
| | - R David Row
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
| | - Travis J Roark
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
| | - John M Antos
- Department of Chemistry, Western Washington University, 516 High Street, Bellingham, WA, 98225, USA
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20
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Suliman M, Santosh V, Seegar TCM, Dalton AC, Schultz KM, Klug CS, Barton WA. Directed evolution provides insight into conformational substrate sampling by SrtA. PLoS One 2017; 12:e0184271. [PMID: 28859178 PMCID: PMC5578623 DOI: 10.1371/journal.pone.0184271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 08/21/2017] [Indexed: 11/19/2022] Open
Abstract
The Sortase family of transpeptidases are found in numerous gram-positive bacteria and involved in divergent physiological processes including anchoring of surface proteins to the cell wall as well as pili assembly. As essential proteins, sortase enzymes have been the focus of considerable interest for the development of novel anti-microbials, however, more recently their function as unique transpeptidases has been exploited for the synthesis of novel bio-conjugates. Yet, for synthetic purposes, SrtA-mediated conjugation suffers from the enzyme's inherently poor catalytic efficiency. Therefore, to identify SrtA variants with improved catalytic efficiency, we used directed evolution to select a catalytically enhanced SrtA enzyme. An analysis of improved SrtA variants in the context of sequence conservation, NMR and x-ray crystal structures, and kinetic data suggests a novel mechanism for catalysis involving large conformational changes that delivers substrate to the active site pocket. Indeed, using DEER-EPR spectroscopy, we reveal that upon substrate binding, SrtA undergoes a large scissors-like conformational change that simultaneously translates the sort-tag substrate to the active site in addition to repositioning key catalytic residues for esterification. A better understanding of Sortase dynamics will significantly enhance future engineering and drug discovery efforts.
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Affiliation(s)
- Muna Suliman
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Vishaka Santosh
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Tom C. M. Seegar
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Annamarie C. Dalton
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Kathryn M. Schultz
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Candice S. Klug
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - William A. Barton
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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21
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Jacobitz AW, Kattke MD, Wereszczynski J, Clubb RT. Sortase Transpeptidases: Structural Biology and Catalytic Mechanism. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 109:223-264. [PMID: 28683919 DOI: 10.1016/bs.apcsb.2017.04.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Gram-positive bacteria use sortase cysteine transpeptidase enzymes to covalently attach proteins to their cell wall and to assemble pili. In pathogenic bacteria sortases are potential drug targets, as many of the proteins that they display on the microbial surface play key roles in the infection process. Moreover, the Staphylococcus aureus Sortase A (SaSrtA) enzyme has been developed into a valuable biochemical reagent because of its ability to ligate biomolecules together in vitro via a covalent peptide bond. Here we review what is known about the structures and catalytic mechanism of sortase enzymes. Based on their primary sequences, most sortase homologs can be classified into six distinct subfamilies, called class A-F enzymes. Atomic structures reveal unique, class-specific variations that support alternate substrate specificities, while structures of sortase enzymes bound to sorting signal mimics shed light onto the molecular basis of substrate recognition. The results of computational studies are reviewed that provide insight into how key reaction intermediates are stabilized during catalysis, as well as the mechanism and dynamics of substrate recognition. Lastly, the reported in vitro activities of sortases are compared, revealing that the transpeptidation activity of SaSrtA is at least 20-fold faster than other sortases that have thus far been characterized. Together, the results of the structural, computational, and biochemical studies discussed in this review begin to reveal how sortases decorate the microbial surface with proteins and pili, and may facilitate ongoing efforts to discover therapeutically useful small molecule inhibitors.
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Affiliation(s)
- Alex W Jacobitz
- The Molecular Biology Institute and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, CA, United States
| | - Michele D Kattke
- The Molecular Biology Institute and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, CA, United States
| | - Jeff Wereszczynski
- Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology, Chicago, IL, United States
| | - Robert T Clubb
- The Molecular Biology Institute and the UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles, CA, United States.
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22
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Disorder-to-Order Transition of an Active-Site Loop Mediates the Allosteric Activation of Sortase A. Biophys J 2016; 109:1706-15. [PMID: 26488662 DOI: 10.1016/j.bpj.2015.08.039] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 11/21/2022] Open
Abstract
Intrinsically disordered proteins and intrinsically disordered regions are implicated in many biological functions and associated with many diseases, but their conformational characterizations are challenging. The disordered β6/β7 loop of Staphylococcus aureus sortase A is involved in the binding of both sorting signals and calcium. Calcium binding allosterically activates the enzyme, but the detailed mechanism has been unclear. Here we adapted the replica exchange with solute tempering method to sample the conformations of the β6/β7 loop, in apo form and in three liganded forms (bound with a sorting signal or calcium or both). The extensive molecular dynamics simulations yield atomic details of the disordered-to-order transition of the loop and suggest a mechanism for allosteric activation: calcium binding results in partial closure and ordering of the loop, thereby leading to preorganization of the binding pocket for the sorting signal. The approach has general applicability to the study of intrinsically disordered regions.
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23
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Shrestha P, Wereszczynski J. Discerning the catalytic mechanism of Staphylococcus aureus sortase A with QM/MM free energy calculations. J Mol Graph Model 2016; 67:33-43. [PMID: 27172839 DOI: 10.1016/j.jmgm.2016.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/08/2016] [Accepted: 04/09/2016] [Indexed: 10/21/2022]
Abstract
Sortases are key virulence factors in Gram-positive bacteria. These enzymes embed surface proteins in the cell wall through a transpeptidation reaction that involves recognizing a penta-peptide "sorting signal" in a target protein, cleaving it, and covalently attaching it to a second substrate that is later inserted into the cell wall. Although well studied, several aspects of the mechanism by which sortases perform these functions remains unclear. In particular, experiments have revealed two potential sorting signal binding motifs: a "Threonine-Out" (Thr-Out) structure in which the catalytically critical threonine residues protrudes into solution, and a "Threonine-In" (Thr-In) configuration in which this residue inserts into the binding site. To determine which of these is the biologically relevant state, we have performed a series of conventional and hybrid quantum mechanics/molecular mechanics (QM/MM) molecular dynamics simulations of the Staphylococcus aureus sortase A (SrtA) enzyme bound to a sorting signal substrate. Through the use of multi-dimensional metadynamics, our simulations were able to both map the acylation mechanism of SrtA in the Thr-In and Thr-Out states, as well as determine the free energy minima and barriers along these reactions. Results indicate that in both states the catalytic mechanisms are similar, however the free energy barriers are lower in the Thr-In configuration, suggesting that Thr-In is the catalytically relevant state. This has important implications for advancing our understanding of the mechanisms of sortase enzymes, as well we for future structure based drug design efforts aimed at inhibiting sortase function in vivo.
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Affiliation(s)
- Pooja Shrestha
- Department of Physics and Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology, 3440 S Dearborn St., Chicago, IL 60616, USA
| | - Jeff Wereszczynski
- Department of Physics and Center for Molecular Study of Condensed Soft Matter, Illinois Institute of Technology, 3440 S Dearborn St., Chicago, IL 60616, USA.
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24
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De Vivo M, Masetti M, Bottegoni G, Cavalli A. Role of Molecular Dynamics and Related Methods in Drug Discovery. J Med Chem 2016; 59:4035-61. [DOI: 10.1021/acs.jmedchem.5b01684] [Citation(s) in RCA: 538] [Impact Index Per Article: 67.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Marco De Vivo
- Laboratory
of Molecular Modeling and Drug Discovery, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
- IAS-5/INM-9 Computational
Biomedicine Forschungszentrum Jülich, Wilhelm-Johnen-Straße, 52428 Jülich, Germany
| | - Matteo Masetti
- Department
of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro
6, I-40126 Bologna, Italy
| | - Giovanni Bottegoni
- CompuNet, Istituto
Italiano di Tecnologia, Via Morego
30, 16163 Genova, Italy
- BiKi Technologies
srl, Via XX Settembre 33/10, 16121 Genova, Italy
| | - Andrea Cavalli
- Department
of Pharmacy and Biotechnology, University of Bologna, Via Belmeloro
6, I-40126 Bologna, Italy
- CompuNet, Istituto
Italiano di Tecnologia, Via Morego
30, 16163 Genova, Italy
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25
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Exploration of multiple Sortase A protein conformations in virtual screening. Sci Rep 2016; 6:20413. [PMID: 26846342 PMCID: PMC4742773 DOI: 10.1038/srep20413] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 01/04/2016] [Indexed: 02/08/2023] Open
Abstract
Methicillin resistant Staphylococcus aureus (MRSA) has become a major health concern which has brought about an urgent need for new therapeutic agents. As the S. aureus Sortase A (SrtA) enzyme contributes to the adherence of the bacteria to the host cells, inhibition thereof by small molecules could be employed as potential antivirulence agents, also towards resistant strains. Albeit several virtual docking SrtA campaigns have been reported, no strongly inhibitatory non-covalent binders have as yet emerged therefrom. In order to better understand the binding modes of small molecules, and the effect of different receptor structures employed in the screening, we herein report on an exploratory study employing 10 known binders and 500 decoys on 100 SrtA structures generated from regular or steered molecular dynamics simulations on four different SrtA crystal/NMR structures. The results suggest a correlation between the protein structural flexibility and the virtual screening performance, and confirm the noted immobilization of the β6/β7 loop upon substrate binding. The NMR structures reported appear to perform slightly better than the Xray-crystal structures, but the binding modes fluctuate tremendously, and it might be suspected that the catalytic site is not necessarily the preferred site of binding for some of the reported active compounds.
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26
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Kornev AP, Taylor SS. Dynamics-Driven Allostery in Protein Kinases. Trends Biochem Sci 2015; 40:628-647. [PMID: 26481499 DOI: 10.1016/j.tibs.2015.09.002] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 08/27/2015] [Accepted: 09/01/2015] [Indexed: 01/05/2023]
Abstract
Protein kinases have very dynamic structures and their functionality strongly depends on their dynamic state. Active kinases reveal a dynamic pattern with residues clustering into semirigid communities that move in μs-ms timescale. Previously detected hydrophobic spines serve as connectors between communities. Communities do not follow the traditional subdomain structure of the kinase core or its secondary structure elements. Instead they are organized around main functional units. Integration of the communities depends on the assembly of the hydrophobic spine and phosphorylation of the activation loop. Single mutations can significantly disrupt the dynamic infrastructure and thereby interfere with long-distance allosteric signaling that propagates throughout the whole molecule. Dynamics is proposed to be the underlying mechanism for allosteric regulation in protein kinases.
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Affiliation(s)
- Alexandr P Kornev
- Department of Pharmacology, University of California at San Diego, La Jolla, CA, 92093, USA.
| | - Susan S Taylor
- Department of Pharmacology, University of California at San Diego, La Jolla, CA, 92093, USA; Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA, 92093, USA.
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27
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Small Molecule Targeting of Protein-Protein Interactions through Allosteric Modulation of Dynamics. Molecules 2015; 20:16435-45. [PMID: 26378508 PMCID: PMC6332300 DOI: 10.3390/molecules200916435] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/06/2015] [Accepted: 09/08/2015] [Indexed: 11/16/2022] Open
Abstract
The protein–protein interaction (PPI) target class is particularly challenging, but offers potential for “first in class” therapies. Most known PPI small molecules are orthosteric inhibitors but many PPI sites may be fundamentally intractable to this approach. One potential alternative is to consider more attractive, remote small molecule pockets; however, on the whole, allostery is poorly understood and difficult to discover and develop. Here we review the literature in order to understand the basis for allostery, especially as it can apply to PPIs. We suggest that the upfront generation of sophisticated and experimentally validated dynamic models of target proteins can aid in target choice and strategy for allosteric intervention to produce the required functional effect.
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28
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Srivastava AK, McDonald LR, Cembran A, Kim J, Masterson LR, McClendon CL, Taylor SS, Veglia G. Synchronous opening and closing motions are essential for cAMP-dependent protein kinase A signaling. Structure 2014; 22:1735-1743. [PMID: 25458836 DOI: 10.1016/j.str.2014.09.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/01/2014] [Accepted: 09/04/2014] [Indexed: 02/07/2023]
Abstract
Conformational fluctuations play a central role in enzymatic catalysis. However, it is not clear how the rates and the coordination of the motions affect the different catalytic steps. Here, we used NMR spectroscopy to analyze the conformational fluctuations of the catalytic subunit of the cAMP-dependent protein kinase (PKA-C), a ubiquitous enzyme involved in a myriad of cell signaling events. We found that the wild-type enzyme undergoes synchronous motions involving several structural elements located in the small lobe of the kinase, which is responsible for nucleotide binding and release. In contrast, a mutation (Y204A) located far from the active site desynchronizes the opening and closing of the active cleft without changing the enzyme's structure, rendering it catalytically inefficient. Since the opening and closing motions govern the rate-determining product release, we conclude that optimal and coherent conformational fluctuations are necessary for efficient turnover of protein kinases.
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Affiliation(s)
- Atul K Srivastava
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Leanna R McDonald
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Alessandro Cembran
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jonggul Kim
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Larry R Masterson
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | - Christopher L McClendon
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA 92093, USA
| | - Susan S Taylor
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA 92093, USA
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA; Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA.
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29
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Abstract
Protein kinases are dynamically regulated signaling proteins that act as switches in the cell by phosphorylating target proteins. To establish a framework for analyzing linkages between structure, function, dynamics, and allostery in protein kinases, we carried out multiple microsecond-scale molecular-dynamics simulations of protein kinase A (PKA), an exemplar active kinase. We identified residue-residue correlated motions based on the concept of mutual information and used the Girvan-Newman method to partition PKA into structurally contiguous "communities." Most of these communities included 40-60 residues and were associated with a particular protein kinase function or a regulatory mechanism, and well-known motifs based on sequence and secondary structure were often split into different communities. The observed community maps were sensitive to the presence of different ligands and provide a new framework for interpreting long-distance allosteric coupling. Communication between different communities was also in agreement with the previously defined architecture of the protein kinase core based on the "hydrophobic spine" network. This finding gives us confidence in suggesting that community analyses can be used for other protein kinases and will provide an efficient tool for structural biologists. The communities also allow us to think about allosteric consequences of mutations that are linked to disease.
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30
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Chan AH, Wereszczynski J, Amer BR, Yi SW, Jung ME, McCammon JA, Clubb RT. Discovery of Staphylococcus aureus sortase A inhibitors using virtual screening and the relaxed complex scheme. Chem Biol Drug Des 2014; 82:418-28. [PMID: 23701677 DOI: 10.1111/cbdd.12167] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/06/2013] [Accepted: 05/19/2013] [Indexed: 01/15/2023]
Abstract
Staphylococcus aureus is the leading cause of hospital-acquired infections in the United States. The emergence of multidrug-resistant strains of S. aureus has created an urgent need for new antibiotics. Staphylococcus aureus uses the sortase A enzyme to display surface virulence factors suggesting that compounds that inhibit its activity will function as potent anti-infective agents. Here, we report the identification of several inhibitors of sortase A using virtual screening methods that employ the relaxed complex scheme, an advanced computer-docking methodology that accounts for protein receptor flexibility. Experimental testing validates that several compounds identified in the screen inhibit the activity of sortase A. A lead compound based on the 2-phenyl-2,3-dihydro-1H-perimidine scaffold is particularly promising, and its binding mechanism was further investigated using molecular dynamics simulations and conducting preliminary structure-activity relationship studies.
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Affiliation(s)
- Albert H Chan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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31
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Biswas T, Pawale VS, Choudhury D, Roy RP. Sorting of LPXTG peptides by archetypal sortase A: role of invariant substrate residues in modulating the enzyme dynamics and conformational signature of a productive substrate. Biochemistry 2014; 53:2515-24. [PMID: 24693991 DOI: 10.1021/bi4016023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Transpeptidase sortase catalyzes the covalent anchoring of surface proteins to the cell wall in Gram-positive bacteria. Sortase A (SrtA) of Staphylococcus aureus is a prototype enzyme and considered a bona fide drug target because several substrate proteins are virulence-related and implicated in pathogenesis. Besides, SrtA also works as a versatile tool in protein engineering. Surface proteins destined for cell wall anchoring contain a LPXTG sequence located in their C-terminus which serves as a substrate recognition motif for SrtA. Recent studies have implicated substrate-induced conformational dynamics in SrtA. In the present work, we have explored the roles of invariant Leu and Pro residues of the substrate in modulating the enzyme dynamics with a view to understand the selection process of a catalytically competent substrate. Overall results of molecular dynamics simulations and experiments carried out with noncanonical substrates and site-directed mutagenesis reveal that the kinked conformation due to Pro in LPXTG is obligatory for productive binding but does not per se control the enzyme dynamics. The Leu residue of the substrate appears to play the crucial role of an anchor to the beta6-beta7 loop directing the conformational transition of the enzyme from an "open" to a "closed" state subsequent to which the Pro residue facilitates the consummation of binding through predominant engagement of the loop and catalytic motif residues in hydrophobic interactions. Collectively, our study provides insights about specificity, tolerance, and conformational sorting of substrate by SrtA. These results have important implications in designing newer substrates and inhibitors for this multifaceted enzyme.
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Affiliation(s)
- Tora Biswas
- National Institute of Immunology, New Delhi 110 067, India
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32
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Molecular Dynamics Simulations of Bromodomains Reveal Binding-Site Flexibility and Multiple Binding Modes of the Natural Ligand Acetyl-Lysine. Isr J Chem 2014. [DOI: 10.1002/ijch.201400009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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