NADH OXIDASE MUTANT HAVING IMPROVED STABILITY AND USE THEREOF

摘要

With respect to water-forming NADH oxidase derived from Streptococcus mutans, there is room for further improvement in stability when actually used for industrial production purposes. Thus, disclosed are: an enzyme that can be used for a long period without undergoing the deterioration in activity during an NAD+ reproduction reaction, namely an enzyme having superior stability, which is produced by altering the functions of water-forming NADH oxidase (which is useful in an NAD+ reproduction system used in a stereoselective oxidation reaction with an oxidoreductase) by a protein engineering technique; and an efficient method for producing a useful substance such as an optically active alcohol and an amino acid. Specifically disclosed is an enzyme function alteration method which enables the improvement in the stability of water-forming NADH oxidase derived from Streptococcus mutans by introducing a mutation into the enzyme properly.