{"title":"Deuterium Solvent Kinetic Isotope Effect on Enzymatic Methyl Transfer Catalyzed by Catechol O-methyltransferase.","authors":"Zhao Zipeng, Li Fangya, Zhang Jianyu","doi":"10.2174/0929866530666230228100703","DOIUrl":null,"url":null,"abstract":"<p><strong>Introduction: </strong>Catechol o-methyltransferase plays a key role in the metabolism of catecholamine neurotransmitters. At present, its catalytic mechanism, overall structure, and kinetic characteristics have been basically clarified, but few people have paid attention to the function of solvents on enzymatic methyl transfer reactions. The influence of solvents on enzymatic reactions has always been a fuzzy hot topic. In addition, as a well-studied typical methyltransferase, COMT is a good test bed for exploring the source of the solvent isotope effect, which is a powerful tool in enzymatic mechanism research.</p><p><strong>Methods: </strong>We have measured the kinetic parameters of methyl transfer catalyzed by COMT in both normal water (H<sub>2</sub>O) and heavy water (D<sub>2</sub>O) by high-performance liquid chromatography (HPLC) in the range of pL 6 ~ 11.</p><p><strong>Results: </strong>The kinetic characteristics of COMT in H<sub>2</sub>O and D<sub>2</sub>O were significantly different under different pH/pD conditions. Significant solvent kinetic isotope effects (SKIE) were obtained, especially inverse solvent kinetic isotope effects (SKIE < 1) were observed in this methyl transfer reaction for the first time.</p><p><strong>Conclusion: </strong>Traditional factors which could interpret the solvent isotope effect were ruled out. It's suggested that the solvent might affect the overall conformation as well as the flexibility of protein through non-covalent forces, thus altering the catalytic activity of COMT and leading to the solvent isotope effect.</p>","PeriodicalId":20736,"journal":{"name":"Protein and Peptide Letters","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Protein and Peptide Letters","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.2174/0929866530666230228100703","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
Introduction: Catechol o-methyltransferase plays a key role in the metabolism of catecholamine neurotransmitters. At present, its catalytic mechanism, overall structure, and kinetic characteristics have been basically clarified, but few people have paid attention to the function of solvents on enzymatic methyl transfer reactions. The influence of solvents on enzymatic reactions has always been a fuzzy hot topic. In addition, as a well-studied typical methyltransferase, COMT is a good test bed for exploring the source of the solvent isotope effect, which is a powerful tool in enzymatic mechanism research.
Methods: We have measured the kinetic parameters of methyl transfer catalyzed by COMT in both normal water (H2O) and heavy water (D2O) by high-performance liquid chromatography (HPLC) in the range of pL 6 ~ 11.
Results: The kinetic characteristics of COMT in H2O and D2O were significantly different under different pH/pD conditions. Significant solvent kinetic isotope effects (SKIE) were obtained, especially inverse solvent kinetic isotope effects (SKIE < 1) were observed in this methyl transfer reaction for the first time.
Conclusion: Traditional factors which could interpret the solvent isotope effect were ruled out. It's suggested that the solvent might affect the overall conformation as well as the flexibility of protein through non-covalent forces, thus altering the catalytic activity of COMT and leading to the solvent isotope effect.
期刊介绍:
Protein & Peptide Letters publishes letters, original research papers, mini-reviews and guest edited issues in all important aspects of protein and peptide research, including structural studies, advances in recombinant expression, function, synthesis, enzymology, immunology, molecular modeling, and drug design. Manuscripts must have a significant element of novelty, timeliness and urgency that merit rapid publication. Reports of crystallization and preliminary structure determination of biologically important proteins are considered only if they include significant new approaches or deal with proteins of immediate importance, and preliminary structure determinations of biologically important proteins. Purely theoretical/review papers should provide new insight into the principles of protein/peptide structure and function. Manuscripts describing computational work should include some experimental data to provide confirmation of the results of calculations.
Protein & Peptide Letters focuses on:
Structure Studies
Advances in Recombinant Expression
Drug Design
Chemical Synthesis
Function
Pharmacology
Enzymology
Conformational Analysis
Immunology
Biotechnology
Protein Engineering
Protein Folding
Sequencing
Molecular Recognition
Purification and Analysis