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Klenow L, Elfageih R, Gao J, Wan H, Withers SG, de Gier JW, Daniels R. Influenza virus and pneumococcal neuraminidases enhance catalysis by similar yet distinct sialic acid-binding strategies. J Biol Chem 2023; 299:102891. [PMID: 36634846 PMCID: PMC9929470 DOI: 10.1016/j.jbc.2023.102891] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Influenza A viruses and the bacterium Streptococcus pneumoniae (pneumococci) both express neuraminidases that catalyze release of sialic acid residues from oligosaccharides and glycoproteins. Although these respiratory pathogen neuraminidases function in a similar environment, it remains unclear if these enzymes use similar mechanisms for sialic acid cleavage. Here, we compared the enzymatic properties of neuraminidases from two influenza A subtypes (N1 and N2) and the pneumococcal strain TIGR4 (NanA, NanB, and NanC). Insect cell-produced N1 and N2 tetramers exhibited calcium-dependent activities and stabilities that varied with pH. In contrast, E. coli-produced NanA, NanB, and NanC were isolated as calcium insensitive monomers with stabilities that were more resistant to pH changes. Using a synthetic substrate (MUNANA), all neuraminidases showed similar pH optimums (pH 6-7) that were primarily defined by changes in catalytic rate rather than substrate binding affinity. Upon using a multivalent substrate (fetuin sialoglycans), much higher specific activities were observed for pneumococcal neuraminidases that contain an additional lectin domain. In virions, N1 and especially N2 also showed enhanced specific activity toward fetuin that was lost upon the addition of detergent, indicating the sialic acid-binding capacity of neighboring hemagglutinin molecules likely contributes to catalysis of natural multivalent substrates. These results demonstrate that influenza and pneumococcal neuraminidases have evolved similar yet distinct strategies to optimize their catalytic activity.
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Affiliation(s)
- Laura Klenow
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Rageia Elfageih
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Jin Gao
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Hongquan Wan
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA
| | - Stephen G. Withers
- Department of Chemistry, University of British Columbia, Vancouver, Canada
| | - Jan-Willem de Gier
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Robert Daniels
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland, USA.
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2
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Yuan L, Zhao Y, Sun XL. Sialidase substrates for Sialdiase assays - activity, specificity, quantification and inhibition. Glycoconj J 2020; 37:513-531. [PMID: 32813176 DOI: 10.1007/s10719-020-09940-0] [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: 05/28/2020] [Revised: 07/08/2020] [Accepted: 08/06/2020] [Indexed: 12/01/2022]
Abstract
Sialidases are glycosidases responsible for the removal of sialic acid (Sia) residues (desialylation) from glycan portions of either glycoproteins or glycolipids. By desialylation, sialidases are able to modulate the functionality and stability of the Sia-containing molecules and are involved in both physiological and pathological pathways. Therefore, evaluation of sialidase activity and specificity is important for understanding the biological significance of desialylation by sialidases and its function and the related molecular mechanisms of the physiological and pathological pathways. In addition, it is essential for developing novel mechanisms and approaches for disease treatment and diagnosis and pathogen detection as well. This review summarizes the most recent sialidase substrates for evaluating sialidase activity and specificity and screening sialidase inhibitors, including (i) general sialidase substrates, (ii) specific sialidase substrates, (iii) native sialidase substrates and (iv) cellular sialidase substrates. This review also provides a brief introduction of recent instrumental methods for quantifying the sialidase activity, such as UV, fluorescence, HPLC and LC-MS methods.
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Affiliation(s)
- Lei Yuan
- Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA.,School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang, 110016, People's Republic of China
| | - Yu Zhao
- Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA
| | - Xue-Long Sun
- Department of Chemistry, Chemical and Biomedical Engineering and Center for Gene Regulation in Health and Disease (GRHD), Cleveland State University, 2121 Euclid Avenue, Cleveland, OH, 44115, USA.
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3
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Song Y, Wang X, Zhang J. Enhancement of bioconversion gangliosides to monosialotetrahexosylganglioside by in situ sialic acid removal and recovery. CAN J CHEM ENG 2019. [DOI: 10.1002/cjce.23591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yansong Song
- State Key Laboratory of Bioreactor EngineeringEast China University of Science and Technology 130 Meilong Road Shanghai 200237 China
| | - Xuedong Wang
- State Key Laboratory of Bioreactor EngineeringEast China University of Science and Technology 130 Meilong Road Shanghai 200237 China
| | - Jianguo Zhang
- Institute of Food Science and Engineering, School of Medical Instrument and Food EngineeringUniversity of Shanghai for Science and Technology 516 Jungong Road Shanghai 200093 China
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4
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Janesch P, Rouha H, Badarau A, Stulik L, Mirkina I, Caccamo M, Havlicek K, Maierhofer B, Weber S, Groß K, Steinhäuser J, Zerbs M, Varga C, Dolezilkova I, Maier S, Zauner G, Nielson N, Power CA, Nagy E. Assessing the function of pneumococcal neuraminidases NanA, NanB and NanC in in vitro and in vivo lung infection models using monoclonal antibodies. Virulence 2019; 9:1521-1538. [PMID: 30289054 PMCID: PMC6177239 DOI: 10.1080/21505594.2018.1520545] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Streptococcus pneumoniae isolates express up to three neuraminidases (sialidases), NanA, NanB and NanC, all of which cleave the terminal sialic acid of glycan-structures that decorate host cell surfaces. Most research has focused on the role of NanA with limited investigations evaluating the roles of all three neuraminidases in host-pathogen interactions. We generated two highly potent monoclonal antibodies (mAbs), one that blocks the enzymatic activity of NanA and one cross-neutralizing NanB and NanC. Total neuraminidase activity of clinical S. pneumoniae isolates could be inhibited by this mAb combination in enzymatic assays. To detect desialylation of cell surfaces by pneumococcal neuraminidases, primary human tracheal/bronchial mucocilial epithelial tissues were infected with S. pneumoniae and stained with peanut lectin. Simultaneous targeting of the neuraminidases was required to prevent desialylation, suggesting that inhibition of NanA alone is not sufficient to preserve terminal lung glycans. Importantly, we also found that all three neuraminidases increased the interaction of S. pneumoniae with human airway epithelial cells. Lectin-staining of lung tissues of mice pre-treated with mAbs before intranasal challenge with S. pneumoniae confirmed that both anti-NanA and anti-NanBC mAbs were required to effectively block desialylation of the respiratory epithelium in vivo. Despite this, no effect on survival, reduction in pulmonary bacterial load, or significant changes in cytokine responses were observed. This suggests that neuraminidases have no pivotal role in this murine pneumonia model that is induced by high bacterial challenge inocula and does not progress from colonization as it happens in the human host.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Karin Groß
- a Arsanis Biosciences , Vienna , Austria
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5
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Xiao K, Wang X, Yu H. Comparative studies of catalytic pathways for Streptococcus pneumoniae sialidases NanA, NanB and NanC. Sci Rep 2019; 9:2157. [PMID: 30770840 PMCID: PMC6377674 DOI: 10.1038/s41598-018-38131-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/14/2018] [Indexed: 11/09/2022] Open
Abstract
Streptococcus pneumoniae (S. pneumoniae) is a leading human pathogen, which takes large responsibility for severe otitis media, acute meningitis and septicaemia. It encodes up to three distinct sialidases: NanA, NanB and NanC, which are promising drug targets. Recent experimental studies have shown that these three sialidases might work together up to the ultimate step, where NanA and NanB produce N-acetylneuraminic acid (Neu5Ac) and 2,7-anhydro-Neu5Ac following the functions of sialidase and intramolecular trans-sialidase, whilst NanC carries on a ping-pong mechanism that produces or removes 2-deoxy-2,3-didehydro-Neu5AC. It is intriguing that these sialidases have similar active sites but operate via three distinct reaction pathways. To clarify this issue, herein we present the first systematic computational investigation on the catalytic pathways for S. pneumoniae NanA, NanB and NanC based on combined quantum mechanics/molecular mechanics simulations, and propose the most preferred routes for the three S. pneumoniae sialidases. Our findings support the mechanisms of NanA and NanC that were proposed by previous experimental studies, whereas the role of water in NanB was found to differ slightly from our current understandings. The mechanistic insights obtained from this work are expected to assist in the design of potent inhibitors targeting these key enzymes for therapeutic applications.
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Affiliation(s)
- Kela Xiao
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2500, Australia.,Molecular Horizons, University of Wollongong, Wollongong, NSW, 2500, Australia
| | - Xingyong Wang
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2500, Australia.,Molecular Horizons, University of Wollongong, Wollongong, NSW, 2500, Australia
| | - Haibo Yu
- School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2500, Australia. .,Molecular Horizons, University of Wollongong, Wollongong, NSW, 2500, Australia. .,Illawarra Health and Medical Research Institute, Wollongong, NSW, 2500, Australia.
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6
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Hľasová Z, Košík I, Ondrejovič M, Miertuš S, Katrlík J. Methods and Current Trends in Determination of Neuraminidase Activity and Evaluation of Neuraminidase Inhibitors. Crit Rev Anal Chem 2018; 49:350-367. [DOI: 10.1080/10408347.2018.1531692] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Zuzana Hľasová
- Department of Biotechnology, Faculty of Natural Sciences of University Ss. Cyril and Methodius, Trnava, Slovakia
| | - Ivan Košík
- Cellular Biology Section, Laboratory of Viral Diseases, NIAID, Bethesda, Maryland, USA
| | - Miroslav Ondrejovič
- Department of Biotechnology, Faculty of Natural Sciences of University Ss. Cyril and Methodius, Trnava, Slovakia
| | - Stanislav Miertuš
- Department of Biotechnology, Faculty of Natural Sciences of University Ss. Cyril and Methodius, Trnava, Slovakia
- International Centre for Applied Research and Sustainable Technology, Bratislava, Slovakia
| | - Jaroslav Katrlík
- Department of Glycobiotechnology, Institute of Chemistry, Slovak Academy of Sciences, Bratislava, Slovakia
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7
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Xiao A, Slack TJ, Li Y, Shi D, Yu H, Li W, Liu Y, Chen X. Streptococcus pneumoniae Sialidase SpNanB-Catalyzed One-Pot Multienzyme (OPME) Synthesis of 2,7-Anhydro-Sialic Acids as Selective Sialidase Inhibitors. J Org Chem 2018; 83:10798-10804. [PMID: 30105908 DOI: 10.1021/acs.joc.8b01519] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Streptococcus pneumoniae sialidase SpNanB is an intramolecular trans-sialidase (IT-sialidase) and a virulence factor that is essential for streptococcal infection of the upper and lower respiratory tract. SpNanB catalyzes the formation of 2,7-anhydro- N-acetylneuraminic acid (2,7-anhydro-Neu5Ac), a potential prebiotic that can be used as the sole carbon source of a common human gut commensal anaerobic bacterium. We report here the development of an efficient one-pot multienzyme (OPME) system for synthesizing 2,7-anhydro-Neu5Ac and its derivatives. Based on a crystal structure analysis, an N-cyclohexyl derivative of 2,7-anhydro-neuraminic acid was designed, synthesized, and shown to be a selective inhibitor against SpNanB and another Streptococcus pneumoniae sialidase SpNanC. This study demonstrates a new strategy of synthesizing 2,7-anhydro-sialic acids in a gram scale and the potential application of their derivatives as selective sialidase inhibitors.
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Affiliation(s)
- An Xiao
- Department of Chemistry , University of California , One Shields Avenue , Davis , California 95616 , United States
| | - Teri J Slack
- Department of Chemistry , University of California , One Shields Avenue , Davis , California 95616 , United States
| | - Yanhong Li
- Department of Chemistry , University of California , One Shields Avenue , Davis , California 95616 , United States
| | - Dashuang Shi
- Children's National Medical Center , 111 Michigan Ave , NW, Washington, DC 20012 , United States
| | - Hai Yu
- Department of Chemistry , University of California , One Shields Avenue , Davis , California 95616 , United States
| | - Wanqing Li
- Department of Chemistry , University of California , One Shields Avenue , Davis , California 95616 , United States
| | - Yang Liu
- Children's National Medical Center , 111 Michigan Ave , NW, Washington, DC 20012 , United States
| | - Xi Chen
- Department of Chemistry , University of California , One Shields Avenue , Davis , California 95616 , United States
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8
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Walther E, Xu Z, Richter M, Kirchmair J, Grienke U, Rollinger JM, Krumbholz A, Saluz HP, Pfister W, Sauerbrei A, Schmidtke M. Dual Acting Neuraminidase Inhibitors Open New Opportunities to Disrupt the Lethal Synergism between Streptococcus pneumoniae and Influenza Virus. Front Microbiol 2016; 7:357. [PMID: 27047471 PMCID: PMC4800182 DOI: 10.3389/fmicb.2016.00357] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/07/2016] [Indexed: 02/01/2023] Open
Abstract
Secondary infections with Streptococcus pneumoniae cause severe pneumonia and enhance lethality during influenza epidemics and pandemics. Structural and functional similarities with viral neuraminidase (NA) suggest that the highly prevalent pneumococcal NAs, NanA and NanB, might contribute to this lethal synergism by supporting viral replication and that dual acting NA inhibitors (NAIs) will disrupt it. To verify this hypothesis, NanA and NanB were expressed in E. coli. After confirming their activity in enzyme assays, in vitro models with influenza virus A/Jena/8178/09 (Jena/8178) and the recombinant NanA or NanB (rNanA and rNanB) were established in A549 and MDCK cells to mimic the role of these pneumococcal NAs during co-infection. Studies on the influence of both NAs on viral receptor expression, spread, and yield revealed a distinct effect of NanA and NanB on viral replication in these in vitro models. Both enzymes were able to support Jena/8178 replication at certain concentrations. This synergism was disrupted by the NAIs oseltamivir, DANA, katsumadain A, and artocarpin exerting an inhibitory effect on viral NA and NanA. Interestingly, katsumadain A and artocarpin inhibited rNanA and rNanB similarly. Zanamivir did not show activity. These results demonstrate a key role of pneumococcal NAs in the lethal synergism with influenza viruses and reveal opportunities for its effective disruption.
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Affiliation(s)
- Elisabeth Walther
- Department of Virology and Antiviral Therapy, Jena University HospitalJena, Germany
| | - Zhongli Xu
- Department of Virology and Antiviral Therapy, Jena University HospitalJena, Germany
| | - Martina Richter
- Department of Virology and Antiviral Therapy, Jena University HospitalJena, Germany
| | | | - Ulrike Grienke
- Department of Pharmacognosy, University of ViennaVienna, Austria
| | | | - Andi Krumbholz
- Institute for Infection Medicine, Christian-Albrecht University of Kiel–University Medical Center Schleswig-Holstein, Campus KielKiel, Germany
| | - Hans P. Saluz
- Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll InstituteJena, Germany
| | - Wolfgang Pfister
- Department of Medical Microbiology, Jena University HospitalJena, Germany
| | - Andreas Sauerbrei
- Department of Virology and Antiviral Therapy, Jena University HospitalJena, Germany
| | - Michaela Schmidtke
- Department of Virology and Antiviral Therapy, Jena University HospitalJena, Germany
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9
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Janapatla RP, Hsu MH, Liao WT, Chien KY, Lee HY, Chiu CH. Low Serum Fetuin-A as a Biomarker to Predict Pneumococcal Necrotizing Pneumonia and Hemolytic Uremic Syndrome in Children. Medicine (Baltimore) 2016; 95:e3221. [PMID: 27043691 PMCID: PMC4998552 DOI: 10.1097/md.0000000000003221] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Streptococcus pneumoniae, a neuraminidase-producing pathogen, can cause invasive pneumococcal disease (IPD) with or without hemolytic uremic syndrome (HUS) in humans. We aimed to identify serum sialoglycoproteins that are targeted by neuraminidases in severe pneumococcal infection. We hypothesized that serum sialoglycoprotein such as fetuin-A can serve as a biomarker to predict IPD or HUS. We constructed serum sialoglycoprotein profiles before and after pneumococcal neuraminidase treatment using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a proteomic approach. An observational study was conducted using clinical data and serum samples from pediatric patients with pneumococcal infection to verify the predictive role of fetuin-A in IPD. Serum fetuin-A levels were determined by enzyme-linked immunosorbent assay. The most abundant serum sialoglycoproteins identified by LC-MS/MS after neuraminidase treatment and peanut lectin capture were immunoglobulins, apolipoproteins, fibrinogens, keratins, complement system proteins, and fetuin-A. Serum fetuin-A levels in the HUS patients were significantly lower (207 ± 80 mg/L, P < 0.001) than in patients with lobar pneumonia (610 ± 190 mg/L) as well as the healthy controls (630 ± 250 mg/L). In comparing HUS with necrotizing pneumonia and lobar pneumonia, the ROC area under the curve was 0.842; a cutoff value of 298 mg/L yielded sensitivity of 92.9% (95% CI: 68.5-98.7%) and specificity of 71.9% (95% CI: 54.6-84.4%). This observational study with validation cohorts of patients with HUS, complicated pneumonia, and lobar pneumonia demonstrates the high performance of low serum fetuin-A levels as a biomarker to predict severe IPD and HUS in children.
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Affiliation(s)
- Rajendra Prasad Janapatla
- From the Molecular Infectious Disease Research Center (RPJ, MHH, W-TL, H-YL, C-HC), Chang Gung Memorial Hospital; Graduate Institute of Biomedical Sciences (K-YC, C-HC); and Division of Pediatric Infectious Diseases (H-YL, C-HC), Department of Pediatrics, Chang Gung Children's Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
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10
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Owen CD, Lukacik P, Potter JA, Sleator O, Taylor GL, Walsh MA. Streptococcus pneumoniae NanC: STRUCTURAL INSIGHTS INTO THE SPECIFICITY AND MECHANISM OF A SIALIDASE THAT PRODUCES A SIALIDASE INHIBITOR. J Biol Chem 2015; 290:27736-48. [PMID: 26370075 PMCID: PMC4646021 DOI: 10.1074/jbc.m115.673632] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Indexed: 12/26/2022] Open
Abstract
Streptococcus pneumoniae is an important human pathogen that causes a range of disease states. Sialidases are important bacterial virulence factors. There are three pneumococcal sialidases: NanA, NanB, and NanC. NanC is an unusual sialidase in that its primary reaction product is 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (Neu5Ac2en, also known as DANA), a nonspecific hydrolytic sialidase inhibitor. The production of Neu5Ac2en from α2–3-linked sialosides by the catalytic domain is confirmed within a crystal structure. A covalent complex with 3-fluoro-β-N-acetylneuraminic acid is also presented, suggesting a common mechanism with other sialidases up to the final step of product formation. A conformation change in an active site hydrophobic loop on ligand binding constricts the entrance to the active site. In addition, the distance between the catalytic acid/base (Asp-315) and the ligand anomeric carbon is unusually short. These features facilitate a novel sialidase reaction in which the final step of product formation is direct abstraction of the C3 proton by the active site aspartic acid, forming Neu5Ac2en. NanC also possesses a carbohydrate-binding module, which is shown to bind α2–3- and α2–6-linked sialosides, as well as N-acetylneuraminic acid, which is captured in the crystal structure following hydration of Neu5Ac2en by NanC. Overall, the pneumococcal sialidases show remarkable mechanistic diversity while maintaining a common structural scaffold.
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Affiliation(s)
- C David Owen
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom
| | - Petra Lukacik
- Diamond Light Source and Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0FA, United Kingdom, and
| | - Jane A Potter
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom
| | - Olivia Sleator
- the Medical Research Council France, c/o European Synchrotron Radiation Facility, BP 220, 38043 Grenoble, France
| | - Garry L Taylor
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews, Fife KY16 9ST, United Kingdom,
| | - Martin A Walsh
- Diamond Light Source and the Medical Research Council France, c/o European Synchrotron Radiation Facility, BP 220, 38043 Grenoble, France
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11
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Rodriguez AC, Kohler JJ. Recognition of diazirine-modified O-GlcNAc by human O-GlcNAcase. MEDCHEMCOMM 2014; 5:1227-1234. [PMID: 25068034 DOI: 10.1039/c4md00164h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The mammalian O-GlcNAc hydrolase (OGA) removes O-GlcNAc from serine and threonine residues on intracellular glycoproteins. OGA activity is sensitive to N-acyl substitutions to O-GlcNAc, with alkyl diazirine-modified O-GlcNAc (O-GlcNDAz) being completely resistant to removal by OGA. Using homology modeling, we identified OGA residues proximal to the N-acyl position of O-GlcNAc substrate. Mutation of one of these residues, C215, results in mutant enzymes that are able to hydrolytically remove O-GlcNDAz from a model compound. Further, the C215A mutant is capable of removing O-GlcNDAz from a peptide substrate. These results can be used to improve metabolism of O-GlcNAc analogs in cells. In addition, the enzyme specificity studies reported here provide new insight into the active site of OGA, an important drug target.
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Affiliation(s)
- Andrea C Rodriguez
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038
| | - Jennifer J Kohler
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390-9038
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