Catalytic cycle of formate dehydrogenase captured by single-molecule conductance
Catalytic cycle of formate dehydrogenase captured by single-molecule conductance
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DOI：
10.1038/s41929-023-00928-1
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发表时间：
2023-03
期刊：
影响因子：
37.8
通讯作者：
Aihui Zhang;Xiaoyan Zhuang;Jia Liu;Jiacheng Huang;Luchun Lin;Yongxiang Tang;Shiqiang Zhao;Ruihao Li;Binju Wang;B. Fang;Wenjing Hong
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文献类型：
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作者：
Aihui Zhang;Xiaoyan Zhuang;Jia Liu;Jiacheng Huang;Luchun Lin;Yongxiang Tang;Shiqiang Zhao;Ruihao Li;Binju Wang;B. Fang;Wenjing Hong
了解酶反应的机制和动力学对于生命科学研究和生物工程至关重要。这里，利用扫描隧道显微镜断裂连接技术，通过其特征电导来区分甲酸脱氢酶催化循环中的不同反应状态，并进一步利用这些电导作为监测博伊丁假丝酵母甲酸脱氢酶催化机制的标记。结合多尺度模拟，我们证明了在甲酸脱氢酶的催化循环过程中，结合的还原型烟酰胺腺嘌呤二核苷酸（NADH）通过原位氢化物转移反应直接转化为烟酰胺腺嘌呤二核苷酸（NAD+）。这种转换并不通过传统的、普遍接受的 Theorell-Chance 机制中调用的脱辅基酶状态进行。这项工作为甲酸脱氢酶的机制提供了有趣的见解，并强调了单分子技术在揭示 NADH/NAD+ 依赖性氧化还原酶催化机制方面的潜力。
Understanding the mechanisms and kinetics of enzymatic reactions is essential for studies of life science and for bioengineering. Here the different reaction states in the catalytic cycle of formate dehydrogenase have been distinguished by their characteristic conductances, using the scanning tunnelling microscope break-junction technique, and these conductances have been further exploited as markers to monitor the catalytic mechanism of formate dehydrogenase fromCandida boidinii. Combined with multiscale simulations, we demonstrate that the bound reduced form of nicotinamide adenine dinucleotide (NADH) converts to nicotinamide adenine dinucleotide (NAD+) directly via a hydride-transfer reaction in situ during the catalytic cycle of formate dehydrogenase. This conversion does not proceed via the apoenzyme state invoked in the conventional, generally accepted Theorell–Chance mechanism. This work provides intriguing insight into the mechanism of formate dehydrogenase and highlights the potential of the single-molecule technique in revealing the catalytic mechanism of NADH/NAD+-dependent oxidoreductases.