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Zou Z, Ji Y, Schwaneberg U. Empowering Site-Specific Bioconjugations In Vitro and In Vivo: Advances in Sortase Engineering and Sortase-Mediated Ligation. Angew Chem Int Ed Engl 2024; 63:e202310910. [PMID: 38081121 DOI: 10.1002/anie.202310910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Indexed: 12/23/2023]
Abstract
Sortase-mediated ligation (SML) has emerged as a powerful and versatile methodology for site-specific protein conjugation, functionalization/labeling, immobilization, and design of biohybrid molecules and systems. However, the broader application of SML faces several challenges, such as limited activity and stability, dependence on calcium ions, and reversible reactions caused by nucleophilic side-products. Over the past decade, protein engineering campaigns and particularly directed evolution, have been extensively employed to overcome sortase limitations, thereby expanding the potential application of SML in multiple directions, including therapeutics, biorthogonal chemistry, biomaterials, and biosensors. This review provides an overview of achieved advancements in sortase engineering and highlights recent progress in utilizing SML in combination with other state-of-the-art chemical and biological methodologies. The aim is to encourage scientists to employ sortases in their conjugation experiments.
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Affiliation(s)
- Zhi Zou
- DWI - Leibniz-Institute for Interactive Materials, Forckenbeckstraβe 50, 52074, Aachen, Germany
- RWTH Aachen University, Institute of Biotechnology, Worringerweg 3, 52074, Aachen, Germany
| | - Yu Ji
- RWTH Aachen University, Institute of Biotechnology, Worringerweg 3, 52074, Aachen, Germany
| | - Ulrich Schwaneberg
- DWI - Leibniz-Institute for Interactive Materials, Forckenbeckstraβe 50, 52074, Aachen, Germany
- RWTH Aachen University, Institute of Biotechnology, Worringerweg 3, 52074, Aachen, Germany
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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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Jiang T, Yuan D, Wang R, Zhao C, Xu Y, Liu Y, Song W, Su X, Wang B. Echinacoside, a promising sortase A inhibitor, combined with vancomycin against murine models of MRSA-induced pneumonia. Med Microbiol Immunol 2023; 212:421-435. [PMID: 37796314 DOI: 10.1007/s00430-023-00782-9] [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: 06/02/2023] [Accepted: 09/12/2023] [Indexed: 10/06/2023]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogenic bacterium responsible for a range of severe infections, such as skin infections, bacteremia, and pneumonia. Due to its antibiotic-resistant nature, current research focuses on targeting its virulence factors. Sortase A (SrtA) is a transpeptidase that anchors surface proteins to the bacterial cell wall and is involved in adhesion and invasion to host cells. Through fluorescence resonance energy transfer (FRET), we identified echinacoside (ECH), a natural polyphenol, as a potential SrtA inhibitor with an IC50 of 38.42 μM in vitro. It was demonstrated that ECH inhibited SrtA-mediated S. aureus fibrinogen binding, surface protein A anchoring, and biofilm formation. The fluorescence quenching assay determined the binding mode of ECH to SrtA and calculated the KA-binding constant of 3.09 × 105 L/mol, demonstrating the direct interaction between the two molecules. Molecular dynamics simulations revealed that ECH-SrtA interactions occurred primarily at the binding sites of A92G, A104G, V168A, G192A, and R197A. Importantly, the combination of ECH and vancomycin offered protection against murine models of MRSA-induced pneumonia. Therefore, ECH may serve as a potential antivirulence agent against S. aureus infections, either alone or in combination with vancomycin.
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Affiliation(s)
- Tao Jiang
- Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Dai Yuan
- Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Rong Wang
- Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Chunhui Zhao
- Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Yangming Xu
- Changchun University of Chinese Medicine, Changchun, 130117, China
| | - Yinghui Liu
- Changchun University of Chinese Medicine, Changchun, 130117, China
- Jilin Provincial People's Hospital, Changchun, 130021, China
| | - Wu Song
- Changchun University of Chinese Medicine, Changchun, 130117, China.
| | - Xin Su
- Changchun University of Chinese Medicine, Changchun, 130117, China.
| | - Bingmei Wang
- Changchun University of Chinese Medicine, Changchun, 130117, China.
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4
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Yadav S, Parijat P, Krishnan V. The crystal structure of sortase C from an early colonizer of dental plaque, Streptococcus sanguinis, reveals an active open-lid conformation. Int J Biol Macromol 2023:125183. [PMID: 37276901 DOI: 10.1016/j.ijbiomac.2023.125183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 05/25/2023] [Accepted: 05/30/2023] [Indexed: 06/07/2023]
Abstract
Dental plaque is a complex microbial biofilm community of many species and a major cause of oral infections and infectious endocarditis. Plaque development begins when primary colonizers attach to oral tissues and undergo coaggregation. Primary colonizers facilitate cellular attachment and inter-bacterial interactions through sortase-dependent pili (or fimbriae) extending out from their cell surface. Consequently, the sortase enzyme is viewed as a potential drug target for controlling biofilm formation and avoiding infection. Streptococcus sanguinis is a primary colonizing bacterium whose pili consist of three different pilin subunits that are assembled together by the pilus-specific (C-type) SsaSrtC sortase. Here, we report on the crystal structure determination of the recombinant wild-type and active-site mutant forms of SsaSrtC. Interestingly, the SsaSrtC structure exhibits an open-lid conformation, although a conserved DPX motif is lacking in the lid. Based on molecular docking and structural analysis, we identified the substrate-binding residues essential for pilin recognition and pilus assembly. We also demonstrated that while recombinant SsaSrtC is enzymatically active toward the five-residue LPNTG sorting motif peptide of the pilins, this activity is significantly reduced by the presence of zinc. We further showed that rutin and α-crocin are potential candidate inhibitors of the SsaSrtC sortase via structure-based virtual screening and inhibition assays. The structural knowledge gained from our study will provide the means to develop new approaches that target pilus-mediated attachment, thereby preventing oral biofilm growth and infection.
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Affiliation(s)
- Smita Yadav
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 121001, India
| | - Priyanka Parijat
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 121001, India
| | - Vengadesan Krishnan
- Laboratory of Structural Biology, Regional Centre for Biotechnology, NCR Biotech Science Cluster, Faridabad 121001, India.
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5
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Obeng EM, Fulcher AJ, Wagstaff KM. Harnessing sortase A transpeptidation for advanced targeted therapeutics and vaccine engineering. Biotechnol Adv 2023; 64:108108. [PMID: 36740026 DOI: 10.1016/j.biotechadv.2023.108108] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 01/29/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023]
Abstract
The engineering of potent prophylactic and therapeutic complexes has always required careful protein modification techniques with seamless capabilities. In this light, methods that favor unobstructed multivalent targeting and correct antigen presentations remain essential and very demanding. Sortase A (SrtA) transpeptidation has exhibited these attributes in various settings over the years. However, its applications for engineering avidity-inspired therapeutics and potent vaccines have yet to be significantly noticed, especially in this era where active targeting and multivalent nanomedications are in great demand. This review briefly presents the SrtA enzyme and its associated transpeptidation activity and describes interesting sortase-mediated protein engineering and chemistry approaches for achieving multivalent therapeutic and antigenic responses. The review further highlights advanced applications in targeted delivery systems, multivalent therapeutics, adoptive cellular therapy, and vaccine engineering. These innovations show the potential of sortase-mediated techniques in facilitating the development of simple plug-and-play nanomedicine technologies against recalcitrant diseases and pandemics such as cancer and viral infections.
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Affiliation(s)
- Eugene M Obeng
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.
| | - Alex J Fulcher
- Monash Micro Imaging, Monash University, Clayton, VIC 3800, Australia
| | - Kylie M Wagstaff
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.
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6
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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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7
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Negi S, Hamori M, Sato A, Shimizu K, Kawahara-Nakagawa Y, Manabe T, Shibata N, Kitagishi H, Mashimo M, Sugiura Y. Transpeptidation reaction mediated by ligand- and metal cofactor-substituted Sortase A from Staphylococcus aureus. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2022. [DOI: 10.1246/bcsj.20220098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Shigeru Negi
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395
| | - Mami Hamori
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395
| | - Ayaka Sato
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395
| | - Kyoko Shimizu
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395
| | - Yuka Kawahara-Nakagawa
- Graduate School of Faculty of Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297
| | - Takayuki Manabe
- Clinical Research Support Center, Asahikawa Medical University Hospital, 2-1-1-1 Midorigaoka Higashi, Asahikawa 078-8510
| | - Nobuhito Shibata
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395
| | - Hiroaki Kitagishi
- Department of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321
| | - Masato Mashimo
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395
| | - Yukio Sugiura
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395
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8
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Morgan HE, Turnbull WB, Webb ME. Challenges in the use of sortase and other peptide ligases for site-specific protein modification. Chem Soc Rev 2022; 51:4121-4145. [PMID: 35510539 PMCID: PMC9126251 DOI: 10.1039/d0cs01148g] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Site-specific protein modification is a widely-used biochemical tool. However, there are many challenges associated with the development of protein modification techniques, in particular, achieving site-specificity, reaction efficiency and versatility. The engineering of peptide ligases and their substrates has been used to address these challenges. This review will focus on sortase, peptidyl asparaginyl ligases (PALs) and variants of subtilisin; detailing how their inherent specificity has been utilised for site-specific protein modification. The review will explore how the engineering of these enzymes and substrates has led to increased reaction efficiency mainly due to enhanced catalytic activity and reduction of reversibility. It will also describe how engineering peptide ligases to broaden their substrate scope is opening up new opportunities to expand the biochemical toolkit, particularly through the development of techniques to conjugate multiple substrates site-specifically onto a protein using orthogonal peptide ligases. We highlight chemical and biochemical strategies taken to optimise peptide and protein modification using peptide ligases.![]()
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Affiliation(s)
- Holly E Morgan
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
| | - W Bruce Turnbull
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
| | - Michael E Webb
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
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9
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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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10
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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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11
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Discovery of Sortase A covalent inhibitors with benzofuranene cyanide structures as potential antibacterial agents against Staphylococcus aureus. Eur J Med Chem 2021; 229:114032. [PMID: 34954590 DOI: 10.1016/j.ejmech.2021.114032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 11/19/2021] [Accepted: 11/28/2021] [Indexed: 11/19/2022]
Abstract
Sortase A (SrtA) is a cysteine transpeptidase of most gram-positive bacteria that is responsible for the anchoring of many surface protein virulence factors to the cell wall. SrtA ablation has demonstrated to alleviate the infection without affecting the viability of bacteria. Herein, a series of benzofuran cyanide derivatives were synthesized and evaluated. Several compounds exhibited excellent inhibitory activity against SrtA with IC50 values from 3.3 μM to 21.8 μM compared with the known SrtA inhibitor pHMB (IC50 = 130 μM). Ⅲ-1, Ⅲ-15, Ⅲ-34 and V-1 showed potent inhibitory effects on biofilm formation with IC50 values from 2.1 μM to 54.2 μM. Invasion assays showed the four compounds caused a decrease of 4%-24.0% in the uptake of the S. aureus strain by 293T cells. Further assay showed that compound Ⅲ-15 decreased the amount of cell wall-associated protein A by 26.5%. Structure-activity relationship and docking studies demonstrated that the acrylonitrile moiety of the compounds played an important role in enhancing the activity. When the double bond of acrylonitrile changed to single bond, the activity was decreased significantly. This indicates that acrylonitrile, which is a Michael receptor, can inhibit the activity of SrtA by covalent binding effectively to the thiol group of Cys184.
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12
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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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13
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van der Sleen LM, Tych KM. Bioconjugation Strategies for Connecting Proteins to DNA-Linkers for Single-Molecule Force-Based Experiments. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:2424. [PMID: 34578744 PMCID: PMC8464727 DOI: 10.3390/nano11092424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 01/10/2023]
Abstract
The mechanical properties of proteins can be studied with single molecule force spectroscopy (SMFS) using optical tweezers, atomic force microscopy and magnetic tweezers. It is common to utilize a flexible linker between the protein and trapped probe to exclude short-range interactions in SMFS experiments. One of the most prevalent linkers is DNA due to its well-defined properties, although attachment strategies between the DNA linker and protein or probe may vary. We will therefore provide a general overview of the currently existing non-covalent and covalent bioconjugation strategies to site-specifically conjugate DNA-linkers to the protein of interest. In the search for a standardized conjugation strategy, considerations include their mechanical properties in the context of SMFS, feasibility of site-directed labeling, labeling efficiency, and costs.
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Affiliation(s)
| | - Katarzyna M. Tych
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands;
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14
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Sequence variation in the β7-β8 loop of bacterial class A sortase enzymes alters substrate selectivity. J Biol Chem 2021; 297:100981. [PMID: 34302812 PMCID: PMC8361268 DOI: 10.1016/j.jbc.2021.100981] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/09/2021] [Accepted: 07/16/2021] [Indexed: 01/03/2023] Open
Abstract
Gram-positive bacteria contain sortase enzymes on their cell surfaces that catalyze transpeptidation reactions critical for proper cellular function. In vitro, sortases are used in sortase-mediated ligation (SML) reactions for a variety of protein engineering applications. Historically, sortase A from Staphylococcus aureus (saSrtA) has been the enzyme of choice to catalyze SML reactions. However, the stringent specificity of saSrtA for the LPXTG sequence motif limits its uses. Here, we describe the impact on substrate selectivity of a structurally conserved loop with a high degree of sequence variability in all classes of sortases. We investigate the contribution of this β7–β8 loop by designing and testing chimeric sortase enzymes. Our chimeras utilize natural sequence variation of class A sortases from eight species engineered into the SrtA sequence from Streptococcus pneumoniae. While some of these chimeric enzymes mimic the activity and selectivity of the WT protein from which the loop sequence was derived (e.g., that of saSrtA), others results in chimeric Streptococcus pneumoniae SrtA enzymes that are able to accommodate a range of residues in the final position of the substrate motif (LPXTX). Using mutagenesis, structural comparisons, and sequence analyses, we identify three interactions facilitated by β7–β8 loop residues that appear to be broadly conserved or converged upon in class A sortase enzymes. These studies provide the foundation for a deeper understanding of sortase target selectivity and can expand the sortase toolbox for future SML applications.
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15
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Freund C, Schwarzer D. Engineered Sortases in Peptide and Protein Chemistry. Chembiochem 2021; 22:1347-1356. [PMID: 33290621 PMCID: PMC8248031 DOI: 10.1002/cbic.202000745] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/07/2020] [Indexed: 12/21/2022]
Abstract
The transpeptidase sortase A of Staphylococcus aureus (Sa-SrtA) is a valuable tool in protein chemistry. The native enzyme anchors surface proteins containing a highly conserved LPxTG sorting motif to a terminal glycine residue of the peptidoglycan layer in Gram-positive bacteria. This reaction is exploited for sortase-mediated ligation (SML), allowing the site-specific linkage of synthetic peptides and recombinant proteins by a native peptide bond. However, the moderate catalytic efficiency and specificity of Sa-SrtA fueled the development of new biocatalysts for SML, including the screening of sortase A variants form microorganisms other than S. aureus and the directed protein evolution of the Sa-SrtA enzyme itself. Novel display platforms and screening formats were developed to isolate sortases with altered properties from mutant libraries. This yielded sortases with strongly enhanced catalytic activity and enzymes recognizing new sorting motifs as substrates. This minireview focuses on recent advances in the field of directed sortase evolution and applications of these tailor-made enzymes in biochemistry.
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Affiliation(s)
- Christian Freund
- Freie Universität BerlinInstitute of Chemistry and BiochemistryThielallee 6314195BerlinGermany
| | - Dirk Schwarzer
- University of TübingenInterfaculty Institute of Biochemistry (IFIB)Auf der Morgenstelle 3472076TübingenGermany
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16
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Zou Z, Nöth M, Jakob F, Schwaneberg U. Designed Streptococcus pyogenes Sortase A Accepts Branched Amines as Nucleophiles in Sortagging. Bioconjug Chem 2020; 31:2476-2481. [DOI: 10.1021/acs.bioconjchem.0c00486] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhi Zou
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- DWI − Leibniz-Institute for Interactive Materials, Forckenbeckstraβe 50, 52074 Aachen, Germany
| | - Maximilian Nöth
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- DWI − Leibniz-Institute for Interactive Materials, Forckenbeckstraβe 50, 52074 Aachen, Germany
| | - Felix Jakob
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- DWI − Leibniz-Institute for Interactive Materials, Forckenbeckstraβe 50, 52074 Aachen, Germany
| | - Ulrich Schwaneberg
- Institute of Biotechnology, RWTH Aachen University, Worringerweg 3, 52074 Aachen, Germany
- DWI − Leibniz-Institute for Interactive Materials, Forckenbeckstraβe 50, 52074 Aachen, Germany
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17
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Wójcik M, Vázquez Torres S, Quax WJ, Boersma YL. Sortase mutants with improved protein thermostability and enzymatic activity obtained by consensus design. Protein Eng Des Sel 2020; 32:555-564. [PMID: 32725168 DOI: 10.1093/protein/gzaa018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 03/16/2020] [Accepted: 07/03/2020] [Indexed: 11/14/2022] Open
Abstract
Staphylococcus aureus sortase A (SaSrtA) is an enzyme that anchors proteins to the cell surface of Gram-positive bacteria. During the transpeptidation reaction performed by SaSrtA, proteins containing an N-terminal glycine can be covalently linked to another protein with a C-terminal LPXTG motif (X being any amino acid). Since the sortase reaction can be performed in vitro as well, it has found many applications in biotechnology. Although sortase-mediated ligation has many advantages, SaSrtA is limited by its low enzymatic activity and dependence on Ca2+. In our study, we evaluated the thermodynamic stability of the SaSrtA wild type and found the enzyme to be stable. We applied consensus analysis to further improve the enzyme's stability while at the same time enhancing the enzyme's activity. As a result, we found thermodynamically improved, more active and Ca2+-independent mutants. We envision that these new variants can be applied in conjugation reactions in low Ca2+ environments.
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Affiliation(s)
- Magdalena Wójcik
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 Groningen, The Netherlands
| | - Susana Vázquez Torres
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 Groningen, The Netherlands
| | - Wim J Quax
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 Groningen, The Netherlands
| | - Ykelien L Boersma
- Department of Chemical and Pharmaceutical Biology, Groningen Research Institute of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 Groningen, The Netherlands
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18
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Insights into the biochemical and functional characterization of sortase E transpeptidase of Corynebacterium glutamicum. Biochem J 2020; 476:3835-3847. [PMID: 31815278 DOI: 10.1042/bcj20190812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 12/30/2022]
Abstract
Most Gram-positive bacteria contain a membrane-bound transpeptidase known as sortase which covalently incorporates the surface proteins on to the cell wall. The sortase-displayed protein structures are involved in cell attachment, nutrient uptake and aerial hyphae formation. Among the six classes of sortase (A-F), sortase A of S. aureus is the well-characterized housekeeping enzyme considered as an ideal drug target and a valuable biochemical reagent for protein engineering. Similar to SrtA, class E sortase in GC rich bacteria plays a housekeeping role which is not studied extensively. However, C. glutamicum ATCC 13032, an industrially important organism known for amino acid production, carries a single putative sortase (NCgl2838) gene but neither in vitro peptide cleavage activity nor biochemical characterizations have been investigated. Here, we identified that the gene is having a sortase activity and analyzed its structural similarity with Cd-SrtF. The purified enzyme showed a greater affinity toward LAXTG substrate with a calculated KM of 12 ± 1 µM, one of the highest affinities reported for this class of enzyme. Moreover, site-directed mutation studies were carried to ascertain the structure functional relationship of Cg-SrtE and all these are new findings which will enable us to perceive exciting protein engineering applications with this class of enzyme from a non-pathogenic microbe.
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19
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Abstract
Protein semisynthesis-defined herein as the assembly of a protein from a combination of synthetic and recombinant fragments-is a burgeoning field of chemical biology that has impacted many areas in the life sciences. In this review, we provide a comprehensive survey of this area. We begin by discussing the various chemical and enzymatic methods now available for the manufacture of custom proteins containing noncoded elements. This section begins with a discussion of methods that are more chemical in origin and ends with those that employ biocatalysts. We also illustrate the commonalities that exist between these seemingly disparate methods and show how this is allowing for the development of integrated chemoenzymatic methods. This methodology discussion provides the technical foundation for the second part of the review where we cover the great many biological problems that have now been addressed using these tools. Finally, we end the piece with a short discussion on the frontiers of the field and the opportunities available for the future.
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Affiliation(s)
| | - Tom W. Muir
- Department of Chemistry, Princeton University, Frick Laboratory, Princeton, New Jersey 08544, United States
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20
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Kang CY, Huang IH, Chou CC, Wu TY, Chang JC, Hsiao YY, Cheng CH, Tsai WJ, Hsu KC, Wang S. Functional analysis of Clostridium difficile sortase B reveals key residues for catalytic activity and substrate specificity. J Biol Chem 2020; 295:3734-3745. [PMID: 32005667 PMCID: PMC7076211 DOI: 10.1074/jbc.ra119.011322] [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: 10/02/2019] [Revised: 01/31/2020] [Indexed: 01/07/2023] Open
Abstract
Most of Gram-positive bacteria anchor surface proteins to the peptidoglycan cell wall by sortase, a cysteine transpeptidase that targets proteins displaying a cell wall sorting signal. Unlike other bacteria, Clostridium difficile, the major human pathogen responsible for antibiotic-associated diarrhea, has only a single functional sortase (SrtB). Sortase's vital importance in bacterial virulence has been long recognized, and C. difficile sortase B (Cd-SrtB) has become an attractive therapeutic target for managing C. difficile infection. A better understanding of the molecular activity of Cd-SrtB may help spur the development of effective agents against C. difficile infection. In this study, using site-directed mutagenesis, biochemical and biophysical tools, LC-MS/MS, and crystallographic analyses, we identified key residues essential for Cd-SrtB catalysis and substrate recognition. To the best of our knowledge, we report the first evidence that a conserved serine residue near the active site participates in the catalytic activity of Cd-SrtB and also SrtB from Staphylococcus aureus The serine residue indispensable for SrtB activity may be involved in stabilizing a thioacyl-enzyme intermediate because it is neither a nucleophilic residue nor a substrate-interacting residue, based on the LC-MS/MS data and available structural models of SrtB-substrate complexes. Furthermore, we also demonstrated that residues 163-168 located on the β6/β7 loop of Cd-SrtB dominate specific recognition of the peptide substrate PPKTG. The results of this work reveal key residues with roles in catalysis and substrate specificity of Cd-SrtB.
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Affiliation(s)
- Chia-Yu Kang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 701, Taiwan
| | - I-Hsiu Huang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 701, Taiwan
| | - Chi-Chi Chou
- Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Tsai-Yu Wu
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 701, Taiwan
| | - Jyun-Cyuan Chang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 701, Taiwan
| | - Yu-Yuan Hsiao
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 300, Taiwan,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 300, Taiwan,Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Cheng-Hsuan Cheng
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 701, Taiwan,Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Wei-Jiun Tsai
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 701, Taiwan,Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
| | - Kai-Cheng Hsu
- Graduate Institute of Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan
| | - Shuying Wang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan,Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan 701, Taiwan,Institute of Basic Medical Science, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan, To whom correspondence should be addressed:
Dept. of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan. Tel.:
886-6-2353535, Ext. 5634; Fax:
886-6-2082705; E-mail:
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21
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Structural studies of Staphylococcus aureus Sortase inhibiton via Conus venom peptides. Arch Biochem Biophys 2019; 671:87-102. [DOI: 10.1016/j.abb.2019.06.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/09/2019] [Accepted: 06/11/2019] [Indexed: 12/13/2022]
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22
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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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23
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Erianin against Staphylococcus aureus Infection via Inhibiting Sortase A. Toxins (Basel) 2018; 10:toxins10100385. [PMID: 30249042 PMCID: PMC6215257 DOI: 10.3390/toxins10100385] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/08/2018] [Accepted: 09/20/2018] [Indexed: 02/04/2023] Open
Abstract
With continuous emergence and widespread of multidrug-resistant Staphylococcus aureus infections, common antibiotics have become ineffective in treating these infections in the clinical setting. Anti-virulence strategies could be novel, effective therapeutic strategies against drug-resistant bacterial infections. Sortase A (srtA), a transpeptidase in gram-positive bacteria, can anchor surface proteins that play a vital role in pathogenesis of these bacteria. SrtA is known as a potential antivirulent drug target to treat bacterial infections. In this study, we found that erianin, a natural bibenzyl compound, could inhibit the activity of srtA in vitro (half maximal inhibitory concentration-IC50 = 20.91 ± 2.31 μg/mL, 65.7 ± 7.2 μM) at subminimum inhibitory concentrations (minimum inhibitory concentrations-MIC = 512 μg/mL against S. aureus). The molecular mechanism underlying the inhibition of srtA by erianin was identified using molecular dynamics simulation: erianin binds to srtA residues Ile182, Val193, Trp194, Arg197, and Ile199, forming a stable bond via hydrophobic interactions. In addition, the activities of S. aureus binding to fibronectin and biofilm formation were inhibited by erianin, when co-culture with S. aureus. In vivo, erianin could improve the survival in mice that infected with S. aureus by tail vein injection. Experimental results showed that erianin is a potential novel therapeutic compound against S. aureus infections via affecting srtA.
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24
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Hou X, Wang M, Wen Y, Ni T, Guan X, Lan L, Zhang N, Zhang A, Yang CG. Quinone skeleton as a new class of irreversible inhibitors against Staphylococcus aureus sortase A. Bioorg Med Chem Lett 2018; 28:1864-1869. [PMID: 29650293 DOI: 10.1016/j.bmcl.2018.04.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/30/2018] [Accepted: 04/03/2018] [Indexed: 01/05/2023]
Abstract
Sortase A (SrtA) anchors surface proteins to the cell wall and aids biofilm formation during infection, which functions as a key virulence factor of important Gram-positive pathogens, such as Staphylococcus aureus. At present researchers need a way in which to validate whether or not SrtA is a druggable target alternative to the conventional antibiotic targets in the mechanism. In this study, we performed a high-throughput screening and identified a new class of potential inhibitors of S. aureus SrtA, which are derived from natural products and contain the quinone skeleton. Compound 283 functions as an irreversible inhibitor that covalently alkylates the active site Cys184 of SrtA. NMR analysis confirms the direct interaction of the small-molecule inhibitor towards SrtA protein. The anchoring of protein A (SpA) to the cell wall and the biofilm formation are significantly attenuated when the S. aureus Newman strain is cultured in the presence of inhibitor. Our study indicates that compound 283 could be a potential hit for the development of new anti-virulence agents against S. aureus infections by covalently targeting SrtA.
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Affiliation(s)
- Xiaochen Hou
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China; University of the Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Meining Wang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China
| | - Yi Wen
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China
| | - Tengfeng Ni
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China
| | - Xiangna Guan
- Ministry of Education, School of Pharmacy, Fudan University, 826 ZhangHeng Road, Shanghai 201203, China
| | - Lefu Lan
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China
| | - Naixia Zhang
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China.
| | - Ao Zhang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China.
| | - Cai-Guang Yang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 ZuChongZhi Road, Shanghai 201203, China.
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25
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Abdul Halim MF, Rodriguez R, Stoltzfus JD, Duggin IG, Pohlschroder M. Conserved residues are critical for Haloferax volcanii archaeosortase catalytic activity: Implications for convergent evolution of the catalytic mechanisms of non-homologous sortases from archaea and bacteria. Mol Microbiol 2018; 108:276-287. [PMID: 29465796 DOI: 10.1111/mmi.13935] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/17/2018] [Indexed: 11/29/2022]
Abstract
Proper protein anchoring is key to the biogenesis of prokaryotic cell surfaces, dynamic, resilient structures that play crucial roles in various cell processes. A novel surface protein anchoring mechanism in Haloferax volcanii depends upon the peptidase archaeosortase A (ArtA) processing C-termini of substrates containing C-terminal tripartite structures and anchoring mature substrates to the cell membrane via intercalation of lipid-modified C-terminal amino acid residues. While this membrane protein lacks clear homology to soluble sortase transpeptidases of Gram-positive bacteria, which also process C-termini of substrates whose C-terminal tripartite structures resemble those of ArtA substrates, archaeosortases do contain conserved cysteine, arginine and arginine/histidine/asparagine residues, reminiscent of His-Cys-Arg residues of sortase catalytic sites. The study presented here shows that ArtAWT -GFP expressed in trans complements ΔartA growth and motility phenotypes, while alanine substitution mutants, Cys173 (C173A), Arg214 (R214A) or Arg253 (R253A), and the serine substitution mutant for Cys173 (C173S), fail to complement these phenotypes. Consistent with sortase active site replacement mutants, ArtAC173A -GFP, ArtAC173S -GFP and ArtAR214A -GFP cannot process substrates, while replacement of the third residue, ArtAR253A -GFP retains some processing activity. These findings support the view that similarities between certain aspects of the structures and functions of the sortases and archaeosortases are the result of convergent evolution.
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Affiliation(s)
| | - Ronald Rodriguez
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Iain G Duggin
- The ithree Institute, University of Technology Sydney, Sydney, NSW, 2007, Australia
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26
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Anchoring of LPXTG-Like Proteins to the Gram-Positive Cell Wall Envelope. Curr Top Microbiol Immunol 2017; 404:159-175. [PMID: 27097813 DOI: 10.1007/82_2016_8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In Gram-positive bacteria, protein precursors with a signal peptide and a cell wall sorting signal (CWSS)-which begins with an LPXTG motif, followed by a hydrophobic domain and a tail of positively charged residues-are targeted to the cell envelope by a transpeptidase enzyme call sortase. Evolution and selective pressure gave rise to six classes of sortase, i.e., SrtA-F. Only class C sortases are capable of polymerizing substrates harboring the pilin motif and CWSS into protein polymers known as pili or fimbriae, whereas the others perform cell wall anchoring functions. Regardless of the products generated from these sortases, the basic principle of sortase-catalyzed transpeptidation is the same. It begins with the cleavage of the LPXTG motif, followed by the cross-linking of this cleaved product at the threonine residue to a nucleophile, i.e., an active amino group of the peptidoglycan stem peptide or the lysine residue of the pilin motif. This chapter will summarize the efforts to identify and characterize sortases and their associated pathways with emphasis on the cell wall anchoring function.
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27
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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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28
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Silvius JR, Leventis R. A Novel “Prebinding” Strategy Dramatically Enhances Sortase-Mediated Coupling of Proteins to Liposomes. Bioconjug Chem 2017; 28:1271-1282. [DOI: 10.1021/acs.bioconjchem.7b00087] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- John R. Silvius
- Department of Biochemistry, McGill University, 3655 Promenade Sir-William-Osler, Montréal, QC, Canada H3G 1A9
| | - Rania Leventis
- Department of Biochemistry, McGill University, 3655 Promenade Sir-William-Osler, Montréal, QC, Canada H3G 1A9
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29
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Das S, Pawale VS, Dadireddy V, Singh AK, Ramakumar S, Roy RP. Structure and specificity of a new class of Ca 2+-independent housekeeping sortase from Streptomyces avermitilis provide insights into its non-canonical substrate preference. J Biol Chem 2017; 292:7244-7257. [PMID: 28270507 DOI: 10.1074/jbc.m117.782037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/06/2017] [Indexed: 11/06/2022] Open
Abstract
Surface proteins in Gram-positive bacteria are incorporated into the cell wall through a peptide ligation reaction catalyzed by transpeptidase sortase. Six main classes (A-F) of sortase have been identified of which class A sortase is meant for housekeeping functions. The prototypic housekeeping sortase A (SaSrtA) from Staphylococcus aureus cleaves LPXTG-containing proteins at the scissile T-G peptide bond and ligates protein-LPXT to the terminal Gly residue of the nascent cross-bridge of peptidoglycan lipid II precursor. Sortase-mediated ligation ("sortagging") of LPXTG-containing substrates and Gly-terminated nucleophiles occurs in vitro as well as in cellulo in the presence of Ca2+ and has been applied extensively for protein conjugations. Although the majority of applications emanate from SaSrtA, low catalytic efficiency, LPXTG specificity restriction, and Ca2+ requirement (particularly for in cellulo applications) remain a drawback. Given that Gram-positive bacteria genomes encode a variety of sortases, natural sortase mining can be a viable complementary approach akin to engineering of wild-type SaSrtA. Here, we describe the structure and specificity of a new class E sortase (SavSrtE) annotated to perform housekeeping roles in Streptomyces avermitilis Biochemical experiments define the attributes of an optimum peptide substrate, demonstrate Ca2+-independent activity, and provide insights about contrasting functional characteristics of SavSrtE and SaSrtA. Crystal structure, substrate docking, and mutagenesis experiments have identified a critical residue that dictates the preference for a non-canonical LAXTG recognition motif over LPXTG. These results have implications for rational tailoring of substrate tolerance in sortases. Besides, Ca2+-independent orthogonal specificity of SavSrtE is likely to expand the sortagging toolkit.
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Affiliation(s)
- Sreetama Das
- From the Department of Physics, Indian Institute of Science, Bangalore 560012, and
| | | | | | | | | | - Rajendra P Roy
- the National Institute of Immunology, Delhi 110067, India
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Wall EA, Johnson AL, Peterson DL, Christie GE. Structural modeling and functional analysis of the essential ribosomal processing protease Prp from Staphylococcus aureus. Mol Microbiol 2017; 104:520-532. [PMID: 28187498 DOI: 10.1111/mmi.13644] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2017] [Indexed: 12/19/2022]
Abstract
In Firmicutes and related bacteria, ribosomal large subunit protein L27 is encoded with a conserved N-terminal extension that is removed to expose residues critical for ribosome function. Bacteria encoding L27 with this N-terminal extension also encode a sequence-specific cysteine protease, Prp, which carries out this cleavage. In this work, we demonstrate that L27 variants with an un-cleavable N-terminal extension, or lacking the extension (pre-cleaved), are unable to complement an L27 deletion in Staphylococcus aureus. This indicates that N-terminal processing of L27 is not only essential but possibly has a regulatory role. Prp represents a new clade of previously uncharacterized cysteine proteases, and the dependence of S. aureus on L27 cleavage by Prp validates the enzyme as a target for potential antibiotic development. To better understand the mechanism of Prp activity, we analyzed Prp enzyme kinetics and substrate preference using a fluorogenic peptide cleavage assay. Molecular modeling and site-directed mutagenesis implicate several residues around the active site in catalysis and substrate binding, and support a structural model in which rearrangement of a flexible loop upon binding of the correct peptide substrate is required for the active site to assume the proper conformation. These findings lay the foundation for the development of antimicrobials that target this novel, essential pathway.
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Affiliation(s)
- Erin A Wall
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Adam L Johnson
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Darrell L Peterson
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
| | - Gail E Christie
- Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA
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31
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Wu Z, Hong H, Zhao X, Wang X. Efficient expression of sortase A from Staphylococcus aureus in Escherichia coli and its enzymatic characterizations. BIORESOUR BIOPROCESS 2017; 4:13. [PMID: 28261538 PMCID: PMC5316389 DOI: 10.1186/s40643-017-0143-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/07/2017] [Indexed: 02/08/2023] Open
Abstract
Background Sortase A (SrtA) is a transpeptidase found in Staphylococcus aureus, which is widely used in site-specific protein modification. However, SrtA was expressed in Escherichia coli (E. coli) in rather low level (ranging from several milligrams to 76.9 mg/L at most). The present study aims to optimize fermentation conditions for improving SrtA expression in E. coli. Results Under the optimized media (0.48 g/L glycerol, 1.37 g/L tryptone, 0.51 g/L yeast extract, MOPS 0.5 g/L, PBS buffer 180 mL/L) and condition (30 °C for 8 h) in a 7-L fermentor, the enzyme activity and the yield of SrtA reached 2458.4 ± 115.9 U/mg DCW and 232.4 ± 21.1 mg/L, respectively, which were higher by 5.8- and 4.5-folds compared with initial conditions, respectively. The yield of SrtA also represented threefold increase than the previously reported maximal level. In addition, the enzymatic characterizations of SrtA (optimal temperature, optimal pH, the influence of metal irons, and tolerance to water-soluble organic solvents) were determined. Conclusions Enhanced expression of SrtA was achieved by optimization of medium and condition. This result will have potential application for production levels of SrtA on an industry scale. Moreover, the detailed enzymatic characterizations of SrtA were examined, which will provide a useful guide for its future application. Electronic supplementary material The online version of this article (doi:10.1186/s40643-017-0143-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhimeng Wu
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, China.,State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing, 100191 China
| | - Haofei Hong
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, China
| | - Xinrui Zhao
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, China
| | - Xun Wang
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, China
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Schmohl L, Bierlmeier J, Gerth F, Freund C, Schwarzer D. Engineering sortase A by screening a second-generation library using phage display. J Pept Sci 2017; 23:631-635. [PMID: 28185387 DOI: 10.1002/psc.2980] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/18/2017] [Accepted: 01/18/2017] [Indexed: 12/29/2022]
Abstract
Sortase-mediated ligation is one of the most commonly used chemo-enzymatic techniques for the site-specific modification of proteins. We have established a new library of sortase mutants for directed evolution of sortase substrate selectivity. Phage display screens of this second-generation library yielded sortase mutants that ligate substrate proteins containing an APxTG or FPxTG recognition sequence instead of the canonical LPxTG sorting motif. These findings indicate that the second-generation sortase library is well suited for sortase engineering in order to increase the versatility of sortase-mediated ligation. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.
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Affiliation(s)
- Lena Schmohl
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, D-72076, Tübingen, Germany
| | - Jan Bierlmeier
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, D-72076, Tübingen, Germany
| | - Fabian Gerth
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, D-14195, Berlin, Germany
| | - Christian Freund
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, D-14195, Berlin, Germany
| | - Dirk Schwarzer
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, D-72076, Tübingen, Germany
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33
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Si L, Li P, Liu X, Luo L. Chinese herb medicine against Sortase A catalyzed transformations, a key role in gram-positive bacterial infection progress. J Enzyme Inhib Med Chem 2016; 31:184-196. [PMID: 27162091 DOI: 10.1080/14756366.2016.1178639] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Many Gram-positive bacteria can anchor their surface proteins to the cell wall peptidoglycan covalently by a common mechanism with Sortase A (SrtA), thus escaping from the host's identification of immune cells. SrtA can complete this anchoring process by cleaving LPXTG motif conserved among these surface proteins and thus these proteins anchor on the cell wall. Moreover, those SrtA mutants lose this capability to anchor these relative proteins, with these bacteria no longer infectious. Therefore, SrtA inhibitors can be promising anti-infective agents to cure bacterial infections. Chinese herb medicines (CHMs) (chosen from Science Citation Index) have exhibited inhibition on SrtA of Gram-positive pathogens irreversibly or reversibly. In general, CHMs are likely to have important long-term impact as new antibacterial compounds and sought after by academia and the pharmaceutical industry. This review mainly focuses on SrtA inhibitors from CHMs and the potential inhibiting mechanism related to chemical structures of compounds in CHMs.
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Affiliation(s)
- Lifang Si
- a School of Bioscience & Bioengineering, South China University of Technology, Guangzhou University Town , Panyu , Guangzhou , China
| | - Pan Li
- a School of Bioscience & Bioengineering, South China University of Technology, Guangzhou University Town , Panyu , Guangzhou , China
| | - Xiong Liu
- a School of Bioscience & Bioengineering, South China University of Technology, Guangzhou University Town , Panyu , Guangzhou , China
| | - Lixin Luo
- a School of Bioscience & Bioengineering, South China University of Technology, Guangzhou University Town , Panyu , Guangzhou , China
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34
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Ismail NF, Lim TS. Site-specific scFv labelling with invertase via Sortase A mechanism as a platform for antibody-antigen detection using the personal glucose meter. Sci Rep 2016; 6:19338. [PMID: 26782912 PMCID: PMC4726117 DOI: 10.1038/srep19338] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 11/17/2015] [Indexed: 12/17/2022] Open
Abstract
Antibody labelling to reporter molecules is gaining popularity due to its many potential applications for diagnostics and therapeutics. However, non-directional bioconjugation methods which are commonly used often results in the loss of target binding capabilities. Therefore, a site-specific enzymatic based bioconjugation such as sortase-mediated transpeptidation allows for a more rapid and efficient method of antibody conjugation for diagnostic applications. Here we describe the utilization of sortase A bioconjugation to conjugate a single chain fragment variable (scFv) to the extracellular invertase (invB) from Zymomonas mobilis with the aim of developing an invertase based immunoassay. In addition, conjugation to enhanced green fluorescent protein (eGFP) was also validated to show the flexibility of the method. The invertase conjugated complex was successfully applied for the detection of antibody-antigen interaction using a personal glucose meter (PGM) for assay readout. The setup was used in both a direct and competitive assay highlighting the robustness of the conjugate for assay development. The method provides an alternative conjugation process to allow easy exchange of antibodies to facilitate rapid development of diagnostic assays for various diseases on the PGM platform.
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Affiliation(s)
- Nur Faezee Ismail
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 Penang, Malaysia
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800 Penang, Malaysia
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35
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Wang L, Bi C, Cai H, Liu B, Zhong X, Deng X, Wang T, Xiang H, Niu X, Wang D. The therapeutic effect of chlorogenic acid against Staphylococcus aureus infection through sortase A inhibition. Front Microbiol 2015; 6:1031. [PMID: 26528244 PMCID: PMC4608362 DOI: 10.3389/fmicb.2015.01031] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/11/2015] [Indexed: 12/17/2022] Open
Abstract
The emergence and wide spread of multi-drug resistant Staphylococcus aureus (S. aureus) requires the development of new therapeutic agents with alternative modes of action. Anti-virulence strategies are hoped to meet that need. Sortase A (SrtA) has attracted great interest as a potential drug target to treat infections caused by S. aureus, as many of the surface proteins displayed by SrtA function as virulence factors by mediating bacterial adhesion to specific organ tissues, invasion of host cells, and evasion of the host-immune responses. It has been suggested that inhibitors of SrtA might be promising candidates for the treatment and/or prevention of S. aureus infections. In this study, we report that chlorogenic acid (CHA), a natural compound that lacks significant anti-S. aureus activity, inhibit the activity of SrtA in vitro (IC50 = 33.86 ± 5.55 μg/ml) and the binding of S. aureus to fibrinogen (Fg). Using molecular dynamics simulations and mutagenesis assays, we further demonstrate that CHA binds to the binding sites of C184 and G192 in the SrtA. In vivo studies demonstrated that CHA prevent mice from S. aureus-induced renal abscess, resulting in a significant survival advantage. These findings indicate that CHA is a promising therapeutic compound against SrtA during S. aureus infections.
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Affiliation(s)
- Lin Wang
- Key Laboratory of Zoonosis Research, Ministry of Education/Institute of Zoonosis/College of Veterinary Medicine, Jilin University Changchun, China
| | - Chongwei Bi
- College of Animal Science, Jilin University Changchun, China
| | - Hongjun Cai
- The College of Animal Science and Technology, Jilin Agricultural University Changchun, China
| | - Bingrun Liu
- College of Animal Science, Jilin University Changchun, China
| | - Xiaobo Zhong
- College of Animal Science, Jilin University Changchun, China
| | - Xuming Deng
- Key Laboratory of Zoonosis Research, Ministry of Education/Institute of Zoonosis/College of Veterinary Medicine, Jilin University Changchun, China
| | - Tiedong Wang
- College of Animal Science, Jilin University Changchun, China
| | - Hua Xiang
- The College of Animal Science and Technology, Jilin Agricultural University Changchun, China
| | - Xiaodi Niu
- Key Laboratory of Zoonosis Research, Ministry of Education/Department of Food Quality and Safety/College of Veterinary Medicine, Jilin University Changchun, China
| | - Dacheng Wang
- College of Animal Science, Jilin University Changchun, China
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Cascioferro S, Raffa D, Maggio B, Raimondi MV, Schillaci D, Daidone G. Sortase A Inhibitors: Recent Advances and Future Perspectives. J Med Chem 2015; 58:9108-23. [DOI: 10.1021/acs.jmedchem.5b00779] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Stella Cascioferro
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Sezione
di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy
- IEMEST, Istituto Euromediterraneo di Scienza e Tecnologia, Via Emerico Amari, 123, 90139 Palermo, Italy
| | - Demetrio Raffa
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Sezione
di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy
| | - Benedetta Maggio
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Sezione
di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy
| | - Maria Valeria Raimondi
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Sezione
di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy
| | - Domenico Schillaci
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Sezione
di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy
| | - Giuseppe Daidone
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Sezione
di Chimica e Tecnologie Farmaceutiche, Università degli Studi di Palermo, Via Archirafi 32, 90123 Palermo, Italy
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Schmohl L, Wagner FR, Schümann M, Krause E, Schwarzer D. Semisynthesis and initial characterization of sortase A mutants containing selenocysteine and homocysteine. Bioorg Med Chem 2015; 23:2883-9. [PMID: 25900629 DOI: 10.1016/j.bmc.2015.03.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/19/2015] [Accepted: 03/21/2015] [Indexed: 12/14/2022]
Abstract
The bacterial transpeptidase sortase A is a well-established tool in protein chemistry and catalyzes the chemoselective ligation of peptides and proteins. During catalysis sortase A cleaves the conserved Leu-Pro-X-Thr-Gly sorting motif at the Thr residue under concomitant thioester formation at active site Cys184. We have used expressed protein ligation (EPL) to generate sortase mutants with Cys184 replaced by selenocysteine (Sec) and homocysteine (Hcy). Sec-sortase showed a moderate 2-3-fold reduction in catalytic activity in contrast to Hcy-sortase which is a poor catalyst with less than 1% of wild-type activity. The sensitivity of the active site nucleophiles towards an alkylation reagent correlated with the pKa values of the mutated residues. Furthermore, the pH-profile of Sec-sortase was shifted to more acidic conditions when compared to the wild-type enzyme. These observations provide information on sortase catalysis and the semisynthetic enzymes might represent useful tools for further biochemical investigations and engineering approaches of sortases A.
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Affiliation(s)
- Lena Schmohl
- Interfaculty Institute of Biochemistry, University of Tuebingen, Hoppe-Seyler-Str. 4, D-72076 Tuebingen, Germany
| | - Felix Roman Wagner
- Interfaculty Institute of Biochemistry, University of Tuebingen, Hoppe-Seyler-Str. 4, D-72076 Tuebingen, Germany
| | - Michael Schümann
- Laboratory of Mass Spectrometry, Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, D-13125 Berlin, Germany
| | - Eberhard Krause
- Laboratory of Mass Spectrometry, Leibniz-Institut für Molekulare Pharmakologie, Robert-Rössle-Strasse 10, D-13125 Berlin, Germany
| | - Dirk Schwarzer
- Interfaculty Institute of Biochemistry, University of Tuebingen, Hoppe-Seyler-Str. 4, D-72076 Tuebingen, Germany.
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Deng FK. Ultrafiltration, a useful method for isolation of intermediates in native chemical ligation exemplified with the total synthesis of Sortase AΔN59. J Pept Sci 2015; 21:257-64. [PMID: 25754699 DOI: 10.1002/psc.2745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 12/23/2014] [Accepted: 12/23/2014] [Indexed: 11/07/2022]
Abstract
In this paper, ultrafiltration was employed to facilitate the isolation of intermediates in native chemical ligation. Depending on the molecular weight cutoff of the membrane used, molecules with different sizes could be purified, separated, or concentrated by the ultrafiltration process. Total chemical synthesis of the polypeptide chain of the enzyme Sortase AΔN59 was used as an example of the application of ultrafiltration in chemical protein synthesis. Sortase A is a ligase that catalyzes transpeptidation reactions between proteins that have C-terminal LPXTG recognition sequence and Gly5- on the peptidoglycan of bacterial cell walls. Ultrafiltration technique facilitated synthesis of Sortase AΔN59 and was a promising tool in isolation of intermediates in native chemical ligation.
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Affiliation(s)
- Fang-kun Deng
- Department of Chemistry, The University of Chicago, 929 East 57th street, Chicago, IL, 60615, USA; Department of Biochemistry, School of Medicine Room1017, Jinan University, Huangpu West Road 601, Tianhe District, Guangzhou, Guangdong Province, 510000, China
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Inactivation of sortase A mediated by metal ATCUN complexes. J Biol Inorg Chem 2014; 19:1327-39. [PMID: 25217034 DOI: 10.1007/s00775-014-1190-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 08/24/2014] [Indexed: 02/07/2023]
Abstract
Catalytic metallopeptides that target the membrane-associated sortase A transpeptidase have been developed and evaluated as irreversible inactivators of SrtA∆N59 (sortase A, lacking the initial membrane-binding domain). The copper-binding GGH tripeptide ATCUN motif was linked to amidated forms of the cell wall sorting signal, LPET and LPETG, as sortase-targeting moieties. The resulting metallopeptides were used to determine half maximal inhibitory concentrations (IC₅₀) and rate constants for time-dependent sortase A inactivation. Michaelis-Menten behavior was observed for the catalytic metallopeptides, and k(cat), K(M) and k(cat)/K(M) parameters were obtained as 0.080 ± 0.002 min⁻¹, 23 ± 2 μM and 0.0035 ± 0.0003 μM⁻¹ min⁻¹, respectively. Concentration-dependent inhibition of SrtA∆N59 by the metallopeptides revealed IC₅₀ values ranging from 570 to 700 µM, while Cu-GGH, which lacked a targeting motif, had no measurable IC₅₀ value (>2,000 µM). Time-dependent inactivation of SrtA revealed a range of catalytic activities, with Cu-GGHGLPETG-NH2 demonstrating the fastest rate of inactivation in the presence of ascorbate and hydrogen peroxide coreactants. The active site of the enzyme comprises residues Cys-184, Arg-197 and His-120. LC-MS/MS analysis of the reaction products demonstrated modification of Cys-184 to cysteine sulfonic acid (+48 amu). Results obtained from a DTNB assay support oxidation of the Cys-184 residue. LC-MS/MS also suggested oxidation of the Arg-197 containing peptide. 2D NMR analysis was performed to assess the possible oxidation of His-120, however, none was observed. These compounds possess the potential for irreversible inactivation of SrtA through oxidative modification of essential residues required for substrate binding.
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40
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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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41
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Deng FK, Zhang L, Wang YT, Schneewind O, Kent SBH. Total Chemical Synthesis of the Enzyme Sortase AΔN59with Full Catalytic Activity. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201310900] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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42
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Total Chemical Synthesis of the Enzyme Sortase AΔN59with Full Catalytic Activity. Angew Chem Int Ed Engl 2014; 53:4662-6. [DOI: 10.1002/anie.201310900] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Indexed: 11/07/2022]
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43
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Jacobitz AW, Wereszczynski J, Yi SW, Amer BR, Huang GL, Nguyen AV, Sawaya MR, Jung ME, McCammon JA, Clubb RT. Structural and computational studies of the Staphylococcus aureus sortase B-substrate complex reveal a substrate-stabilized oxyanion hole. J Biol Chem 2014; 289:8891-902. [PMID: 24519933 DOI: 10.1074/jbc.m113.509273] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sortase cysteine transpeptidases covalently attach proteins to the bacterial cell wall or assemble fiber-like pili that promote bacterial adhesion. Members of this enzyme superfamily are widely distributed in Gram-positive bacteria that frequently utilize multiple sortases to elaborate their peptidoglycan. Sortases catalyze transpeptidation using a conserved active site His-Cys-Arg triad that joins a sorting signal located at the C terminus of their protein substrate to an amino nucleophile located on the cell surface. However, despite extensive study, the catalytic mechanism and molecular basis of substrate recognition remains poorly understood. Here we report the crystal structure of the Staphylococcus aureus sortase B enzyme in a covalent complex with an analog of its NPQTN sorting signal substrate, revealing the structural basis through which it displays the IsdC protein involved in heme-iron scavenging from human hemoglobin. The results of computational modeling, molecular dynamics simulations, and targeted amino acid mutagenesis indicate that the backbone amide of Glu(224) and the side chain of Arg(233) form an oxyanion hole in sortase B that stabilizes high energy tetrahedral catalytic intermediates. Surprisingly, a highly conserved threonine residue within the bound sorting signal substrate facilitates construction of the oxyanion hole by stabilizing the position of the active site arginine residue via hydrogen bonding. Molecular dynamics simulations and primary sequence conservation suggest that the sorting signal-stabilized oxyanion hole is a universal feature of enzymes within the sortase superfamily.
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Kahlon AK, Negi AS, Kumari R, Srivastava KK, Kumar S, Darokar MP, Sharma A. Identification of 1-chloro-2-formyl indenes and tetralenes as novel antistaphylococcal agents exhibiting sortase A inhibition. Appl Microbiol Biotechnol 2013; 98:2041-51. [DOI: 10.1007/s00253-013-5036-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 06/01/2013] [Accepted: 06/04/2013] [Indexed: 02/05/2023]
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Kappel K, Wereszczynski J, Clubb RT, McCammon JA. The binding mechanism, multiple binding modes, and allosteric regulation of Staphylococcus aureus Sortase A probed by molecular dynamics simulations. Protein Sci 2013; 21:1858-71. [PMID: 23023444 DOI: 10.1002/pro.2168] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/27/2012] [Accepted: 09/14/2012] [Indexed: 11/05/2022]
Abstract
Sortase enzymes are vitally important for the virulence of gram-positive bacteria as they play a key role in the attachment of surface proteins to the cell wall. These enzymes recognize a specific sorting sequence in proteins destined to be displayed on the surface of the bacteria and catalyze the transpeptidation reaction that links it to a cell wall precursor molecule. Because of their role in establishing pathogenicity, and in light of the recent rise of antibiotic-resistant bacterial strains, sortase enzymes are novel drug targets. Here, we present a study of the prototypical sortase protein Staphylococcus aureus Sortase A (SrtA). Both conventional and accelerated molecular dynamics simulations of S. aureus SrtA in its apo state and when bound to an LPATG sorting signal (SS) were performed. Results support a binding mechanism that may be characterized as conformational selection followed by induced fit. Additionally, the SS was found to adopt multiple metastable states, thus resolving discrepancies between binding conformations in previously reported experimental structures. Finally, correlation analysis reveals that the SS actively affects allosteric pathways throughout the protein that connect the first and the second substrate binding sites, which are proposed to be located on opposing faces of the protein. Overall, these calculations shed new light on the role of dynamics in the binding mechanism and function of sortase enzymes.
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Affiliation(s)
- Kalli Kappel
- Bioengineering Department, University of California, San Diego, La Jolla, California 92093, USA
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Steinhagen M, Zunker K, Nordsieck K, Beck-Sickinger AG. Large scale modification of biomolecules using immobilized sortase A from Staphylococcus aureus. Bioorg Med Chem 2013; 21:3504-10. [PMID: 23598248 DOI: 10.1016/j.bmc.2013.03.039] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 03/02/2013] [Accepted: 03/11/2013] [Indexed: 01/24/2023]
Abstract
Recently, sortase A (SrtA) from Staphyloccus aureus moved into the focus of bioscience because of its ability to incorporate site specific modifications into proteins. The enzyme was mostly used to modify target proteins in an analytical scale, to study biomolecules in their cellular context. In this study, we show the applicability of SrtA mediated ligation for site specific modification of proteins in a large scale. Therefore, the reaction was first optimized using peptides and subsequently new reaction conditions were applied for the large scale biotinylation of interleukin-8. Furthermore, we established C-terminal immobilization of the SrtA on a PEG based resin and could demonstrate maintaining enzymatic activity. Immobilized SrtA significantly facilitates previous ligation protocols as the enzyme can be easily recycled. Also, the removal of excess reaction solution and the whole washing process is significantly accelerated, as centrifugation or filtration techniques can be applied instead of time-consuming chromatography steps.
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Affiliation(s)
- Max Steinhagen
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, Brüderstr. 34, 04103 Leipzig, Germany.
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Williamson DJ, Fascione MA, Webb ME, Turnbull WB. Efficient N-Terminal Labeling of Proteins by Use of Sortase. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201204538] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Williamson DJ, Fascione MA, Webb ME, Turnbull WB. Efficient N-terminal labeling of proteins by use of sortase. Angew Chem Int Ed Engl 2012; 51:9377-80. [PMID: 22890696 DOI: 10.1002/anie.201204538] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Indexed: 01/30/2023]
Affiliation(s)
- Daniel J Williamson
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
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Moritsugu K, Terada T, Kidera A. Disorder-to-order transition of an intrinsically disordered region of sortase revealed by multiscale enhanced sampling. J Am Chem Soc 2012; 134:7094-101. [PMID: 22468560 DOI: 10.1021/ja3008402] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular functions of intrinsically disordered proteins (IDPs) or intrinsically disordered regions (IDRs), such as molecular recognition and cellular signaling, are ascribed to dynamic changes in the conformational space in response to binding of target molecules. Sortase, a transpeptitase in Gram-positive bacteria, has an IDR in a loop which undergoes a disordered-to-ordered transition (called "disordered loop"), accompanying a tilt of another loop ("dynamic loop"), upon binding of a signal peptide and a calcium ion. In this study, all-atom conformational ensembles of sortase were calculated for the four different binding states (with/without the peptide and with/without a calcium ion) by the multiscale enhanced sampling (MSES) simulation to examine how the binding of the peptide and/or calcium influences the conformational ensemble. The MSES is a multiscale and multicopy simulation method that allows an enhanced sampling of the all-atom model of large proteins including explicit solvent. A 100 ns MSES simulation of the ligand-free sortase using 20 replicas (in total 2 μs) demonstrated large flexibility in both the disordered and dynamic loops; however, their distributions were not random but had a clear preference which populates the N-terminal part of the disordered loop near the bound form. The MSES simulations of the three binding states clarified the allosteric mechanism of sortase: the N- and C-terminal parts of the disordered loop undergo a disorder-to-order transition independently of each other upon binding of the peptide and a calcium ion, respectively; however, upon binding of both ligands, the two parts work cooperatively to stabilize the bound peptide.
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Affiliation(s)
- Kei Moritsugu
- Research Program for Computational Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
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Sortase-conjugation generates a capsule vaccine that protects guinea pigs against Bacillus anthracis. Vaccine 2012; 30:3435-44. [PMID: 22449424 DOI: 10.1016/j.vaccine.2012.03.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 03/06/2012] [Accepted: 03/12/2012] [Indexed: 11/21/2022]
Abstract
Capsules protect bacteria against phagocytic clearance. Capsular polysaccharides or polyglutamates have evolved also to resist antigen presentation by immune cells, thereby interfering with the production of opsonophagocytic antibodies. Linking capsular material to a carrier protein stimulates its presentation to the immune system. For many conjugate vaccines this is achieved by a process of random chemical cross-linking. Here we describe a new technology, designated sortase-conjugation, which generates a single amide bond between the C-terminal end of a carrier protein and the capsular material. Sortase-conjugation was used to link the poly-D-γ-glutamic acid (PDGA) capsule of Bacillus anthracis to the receptor binding domain (D4) of protective antigen (PagA). When used as a vaccine, PDGA-D4 conjugate elicited robust antibody responses against both capsule and D4. Immunization with PDGA-D4 afforded guinea pigs complete protection against anthrax challenge with wild-type or pagA mutant B. anthracis Ames.
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