The utilization of cofactor-dependent redox enzymes in bioprocess technologies requires low cost cofactor regeneration methods. PEGylated NAD(H) (PEG-NAD(H)) has been utilized in enzyme membrane reactors as a means to recover the cofactor; however, there is a lack of understanding of the effect of PEGylation on enzymatic activity, especially on the relationship between biocatalysis and transport phenomena. To explore this further, two redox enzymes (formate dehydrogenase (FDH) from Saccharomyces cerevisiae and NAD(H)-dependent d-lactate dehydrogenase (nLDH) from Escherichia coli) have been chosen and the kinetic effects caused by cofactor modifications (with PEG of three different chain lengths) have been investigated. The PEGylation did not impact the cofactor dissociation constants and mass transfer was not the rate-limiting step in biocatalysis for either enzyme. However, the PEG chain length had different impacts on the formation of enzyme/cofactor and/or enzyme/cofactor/substrate ternary complexes for the enzymes. © 2017 American Institute of Chemical Engineers AIChE J, 2017

中文翻译：

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动力学和转运对辅酶聚乙二醇化的酶促生物催化的影响

在生物加工技术中利用依赖辅因子的氧化还原酶需要低成本的辅因子再生方法。聚乙二醇化的NAD（H）（PEG-NAD（H））已在酶膜反应器中用作回收辅因子的手段；然而，对PEG化对酶活性，特别是对生物催化和运输现象之间关系的影响缺乏了解。探索来自酿酒酵母和NAD（H） -依赖性此进一步，二氧化还原酶（甲酸脱氢酶（FDH）d选择了来自大肠杆菌的α-乳酸脱氢酶（nLDH），并研究了辅因子修饰（使用三种不同链长的PEG）引起的动力学效应。聚乙二醇化不会影响辅因子的解离常数，而且传质也不是任何一种酶在生物催化中的限速步骤。然而，PEG链长度对酶的酶/辅因子和/或酶/辅因子/底物三元复合物的形成具有不同的影响。©2017美国化学工程师学会AIChE J，2017