Abstract

Human catechol-O-methyltransferase, a key enzyme related to neurotransmitter metabolism, catalyses a methyl transfer from S-adenosylmethionine to catechol. Although extensive studies aim to understand the enzyme mechanisms, the connection of protein dynamics and enzyme catalysis is still not clear. Here, W38in (Trp143Phe) and W38in/Y68A (Trp143Phe with Tyr68Ala) mutants were carried out to study the relationship of dynamics and catalysis in nano-second timescale using time-resolved fluorescence lifetimes and Stokes shifts in various solvents. The comprehensive data implied the mutant W38in/Y68A with lower activity is more rigid than the ‘WT’−W38in, suggesting the importance of flexibility at residue 38 to maintain the optimal catalysis.

中文翻译：

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邻苯二酚-O-甲基转移酶系统中38位关键残基的纳秒蛋白质动力学：时间分辨荧光研究。

摘要

人儿茶酚-O-甲基转移酶是一种与神经递质代谢有关的关键酶，可催化从S-腺苷甲硫氨酸向儿茶酚的甲基转移。尽管广泛的研究旨在了解酶的机制，但蛋白质动力学和酶催化的联系仍不清楚。在这里，进行了W38in（Trp143Phe）和W38in / Y68A（带有Tyr68Ala的Trp143Phe）突变体的研究，利用时间分辨的荧光寿命和在各种溶剂中的斯托克斯位移研究了纳秒级时域动力学和催化的关系。综合数据表明，具有较低活性的突变体W38in / Y68A比'WT'-W38in具有更高的刚性，这表明在残基38处保持柔韧性对于维持最佳催化作用至关重要。