Elimination of a Free Cysteine by Creation of a Disulfide Bond Increases the Activity and Stability of Candida boidinii Formate Dehydrogenase.

ABSTRACT: NAD⁺-dependent formate dehydrogenase (FDH; EC 1.2.1.2) is an industrial enzyme widely used for NADH regeneration. However, enzyme inactivation caused by the oxidation of cysteine residues is a flaw of native FDH. In this study, we relieved the oxidation of the free cysteine of FDH from Candida boidinii (CboFDH) through the construction of disulfide bonds between A10 and C23 as well as I239 and C262. Variants A10C, I239C, and A10C/I239C were obtained by the site-directed mutagenesis and their properties were studied. Results showed that there were no significant changes in the optimum temperature and pH between variants and wild-type CboFDH. However, the stabilities of all variant enzymes were improved. Specifically, the CboFDH variant A10C (A10C_fdh) showed a significa

SUBMITTER: Zheng J 

PROVIDER: S-EPMC5203636 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature