{"title":"Chemical modification of Arthrobacter sarcosine oxidase by N-methylisothiazolinone reduces reactivity toward oxygen.","authors":"Fuka Toyama, Hironori Kimura, Yuqi Zhang, Yoshiaki Nishiya","doi":"10.1093/bbb/zbae039","DOIUrl":null,"url":null,"abstract":"<p><p>N-Methylisothiazolinone (MIT) is a thiol group modifier and antimicrobial agent. Arthrobacter sarcosine oxidase (SoxA), a diagnostic enzyme for assaying creatinine, loses its activity upon the addition of MIT, and its inactivation mechanism remains unclear. In this study, SoxA was chemically modified using MIT (mo-SoxA), and its structural and chemical properties were characterized. Spectral analysis data, oxygen consumption rates, and reactions were compared between intact SoxA and mo-SoxA. These demonstrate that the oxidative half-reaction toward oxygen is inhibited by MIT modification. The oxidase activity of mo-SoxA was approximately 2.1% of that of intact SoxA, and its dehydrogenase activity was approximately 4.2 times higher. The C-to-S mutants revealed that cooperative modification of 2 specific cysteine residues caused a drastic change in the enzyme reaction mode. Based on the modeled tertiary structures, the putative entrance for oxygen uptake is predicted to be blocked by the chemical modification of the 2 cysteine residues.</p>","PeriodicalId":9175,"journal":{"name":"Bioscience, Biotechnology, and Biochemistry","volume":null,"pages":null},"PeriodicalIF":1.4000,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bioscience, Biotechnology, and Biochemistry","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1093/bbb/zbae039","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
N-Methylisothiazolinone (MIT) is a thiol group modifier and antimicrobial agent. Arthrobacter sarcosine oxidase (SoxA), a diagnostic enzyme for assaying creatinine, loses its activity upon the addition of MIT, and its inactivation mechanism remains unclear. In this study, SoxA was chemically modified using MIT (mo-SoxA), and its structural and chemical properties were characterized. Spectral analysis data, oxygen consumption rates, and reactions were compared between intact SoxA and mo-SoxA. These demonstrate that the oxidative half-reaction toward oxygen is inhibited by MIT modification. The oxidase activity of mo-SoxA was approximately 2.1% of that of intact SoxA, and its dehydrogenase activity was approximately 4.2 times higher. The C-to-S mutants revealed that cooperative modification of 2 specific cysteine residues caused a drastic change in the enzyme reaction mode. Based on the modeled tertiary structures, the putative entrance for oxygen uptake is predicted to be blocked by the chemical modification of the 2 cysteine residues.
期刊介绍:
Bioscience, Biotechnology, and Biochemistry publishes high-quality papers providing chemical and biological analyses of vital phenomena exhibited by animals, plants, and microorganisms, the chemical structures and functions of their products, and related matters. The Journal plays a major role in communicating to a global audience outstanding basic and applied research in all fields subsumed by the Japan Society for Bioscience, Biotechnology, and Agrochemistry (JSBBA).