N20D/N116E Combined Mutant Downward Shifted the pH Optimum of Bacillus subtilis NADH Oxidase.

ABSTRACT: Cofactor regeneration is indispensable to avoid the addition of large quantities of cofactor NADH or NAD⁺ in oxidation-reduction reactions. Water-forming NADH oxidase (Nox) has attracted substantive attention as it can oxidize cytosolic NADH to NAD⁺ without concomitant accumulation of by-products. However, its applications have some limitations in some oxidation-reduction processes when its optimum pH is different from its coupled enzymes. In this study, to modify the optimum pH of BsNox, fifteen relevant candidates of site-directed mutations were selected based on surface charge rational design. As predicted, the substitution of this asparagine residue with an aspartic acid residue (N22D) or with a glutamic acid residue (N116E) shifts its pH optimum from 9.0 to 7.0.

SUBMITTER: Yang T 

PROVIDER: S-EPMC10135872 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature