Chris Whittington, Ajay Sharma, S. Gage Hill, Anthony T. Iavarone, Brian M. Hoffman and Adam R. Offenbacher*,
{"title":"N-糖基化对蛋白结构和动力学的影响与 M. oryzae 脂氧合酶的酶促 C-H 活化有关","authors":"Chris Whittington, Ajay Sharma, S. Gage Hill, Anthony T. Iavarone, Brian M. Hoffman and Adam R. Offenbacher*, ","doi":"10.1021/acs.biochem.4c00109","DOIUrl":null,"url":null,"abstract":"<p >Lipoxygenases (LOXs) from pathogenic fungi are potential therapeutic targets for defense against plant and select human diseases. In contrast to the canonical LOXs in plants and animals, fungal LOXs are unique in having appended <i>N</i>-linked glycans. Such important post-translational modifications (PTMs) endow proteins with altered structure, stability, and/or function. In this study, we present the structural and functional outcomes of removing or altering these surface carbohydrates on the LOX from the devastating rice blast fungus, <i>M. oryzae</i>, <i>Mo</i>LOX. Alteration of the PTMs did notinfluence the active site enzyme–substrate ground state structures as visualized by electron–nuclear double resonance (ENDOR) spectroscopy. However, removal of the eight <i>N</i>-linked glycans by asparagine-to-glutamine mutagenesis nonetheless led to a change in substrate selectivity and an elevated activation energy for the reaction with substrate linoleic acid, as determined by kinetic measurements. Comparative hydrogen–deuterium exchange mass spectrometry (HDX-MS) analysis of wild-type and Asn-to-Gln <i>Mo</i>LOX variants revealed a regionally defined impact on the dynamics of the arched helix that covers the active site. Guided by these HDX results, a single glycan sequon knockout was generated at position 72, and its comparative substrate selectivity from kinetics nearly matched that of the Asn-to-Gln variant. The cumulative data from model glyco-enzyme <i>Mo</i>LOX showcase how the presence, alteration, or removal of even a single <i>N</i>-linked glycan can influence the structural integrity and dynamics of the protein that are linked to an enzyme’s catalytic proficiency, while indicating that extensive glycosylation protects the enzyme during pathogenesis by protecting it from protease degradation.</p>","PeriodicalId":28,"journal":{"name":"Biochemistry Biochemistry","volume":null,"pages":null},"PeriodicalIF":2.9000,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Impact of N-Glycosylation on Protein Structure and Dynamics Linked to Enzymatic C–H Activation in the M. oryzae Lipoxygenase\",\"authors\":\"Chris Whittington, Ajay Sharma, S. Gage Hill, Anthony T. Iavarone, Brian M. Hoffman and Adam R. Offenbacher*, \",\"doi\":\"10.1021/acs.biochem.4c00109\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >Lipoxygenases (LOXs) from pathogenic fungi are potential therapeutic targets for defense against plant and select human diseases. In contrast to the canonical LOXs in plants and animals, fungal LOXs are unique in having appended <i>N</i>-linked glycans. Such important post-translational modifications (PTMs) endow proteins with altered structure, stability, and/or function. In this study, we present the structural and functional outcomes of removing or altering these surface carbohydrates on the LOX from the devastating rice blast fungus, <i>M. oryzae</i>, <i>Mo</i>LOX. Alteration of the PTMs did notinfluence the active site enzyme–substrate ground state structures as visualized by electron–nuclear double resonance (ENDOR) spectroscopy. However, removal of the eight <i>N</i>-linked glycans by asparagine-to-glutamine mutagenesis nonetheless led to a change in substrate selectivity and an elevated activation energy for the reaction with substrate linoleic acid, as determined by kinetic measurements. Comparative hydrogen–deuterium exchange mass spectrometry (HDX-MS) analysis of wild-type and Asn-to-Gln <i>Mo</i>LOX variants revealed a regionally defined impact on the dynamics of the arched helix that covers the active site. Guided by these HDX results, a single glycan sequon knockout was generated at position 72, and its comparative substrate selectivity from kinetics nearly matched that of the Asn-to-Gln variant. The cumulative data from model glyco-enzyme <i>Mo</i>LOX showcase how the presence, alteration, or removal of even a single <i>N</i>-linked glycan can influence the structural integrity and dynamics of the protein that are linked to an enzyme’s catalytic proficiency, while indicating that extensive glycosylation protects the enzyme during pathogenesis by protecting it from protease degradation.</p>\",\"PeriodicalId\":28,\"journal\":{\"name\":\"Biochemistry Biochemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.9000,\"publicationDate\":\"2024-05-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Biochemistry Biochemistry\",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/acs.biochem.4c00109\",\"RegionNum\":3,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"BIOCHEMISTRY & MOLECULAR BIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Biochemistry Biochemistry","FirstCategoryId":"1","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.biochem.4c00109","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
Impact of N-Glycosylation on Protein Structure and Dynamics Linked to Enzymatic C–H Activation in the M. oryzae Lipoxygenase
Lipoxygenases (LOXs) from pathogenic fungi are potential therapeutic targets for defense against plant and select human diseases. In contrast to the canonical LOXs in plants and animals, fungal LOXs are unique in having appended N-linked glycans. Such important post-translational modifications (PTMs) endow proteins with altered structure, stability, and/or function. In this study, we present the structural and functional outcomes of removing or altering these surface carbohydrates on the LOX from the devastating rice blast fungus, M. oryzae, MoLOX. Alteration of the PTMs did notinfluence the active site enzyme–substrate ground state structures as visualized by electron–nuclear double resonance (ENDOR) spectroscopy. However, removal of the eight N-linked glycans by asparagine-to-glutamine mutagenesis nonetheless led to a change in substrate selectivity and an elevated activation energy for the reaction with substrate linoleic acid, as determined by kinetic measurements. Comparative hydrogen–deuterium exchange mass spectrometry (HDX-MS) analysis of wild-type and Asn-to-Gln MoLOX variants revealed a regionally defined impact on the dynamics of the arched helix that covers the active site. Guided by these HDX results, a single glycan sequon knockout was generated at position 72, and its comparative substrate selectivity from kinetics nearly matched that of the Asn-to-Gln variant. The cumulative data from model glyco-enzyme MoLOX showcase how the presence, alteration, or removal of even a single N-linked glycan can influence the structural integrity and dynamics of the protein that are linked to an enzyme’s catalytic proficiency, while indicating that extensive glycosylation protects the enzyme during pathogenesis by protecting it from protease degradation.
期刊介绍:
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