NADH OXIDASE MUTANT HAVING IMPROVED STABILITY AND USE THEREOF

摘要

Water-forming NADH oxidase derived from Streptococcus mutans should be further improved in terms of stability for practical use in industrial production. An object of the present invention is to provide an enzyme that is obtained through modification of a water-forming NADH oxidase, which is useful as an NAD+ regeneration system for stereoselective oxidation catalyzed by an oxidoreductase, by protein engineering techniques so that the enzyme can withstand long-term use without exhibiting a reduction of its activity for the regeneration of NAD+, that is, an enzyme having improved stability, and to provide a method for efficiently producing a useful substance such as an optically active alcohol or amino acid. The present invention relates to an enzyme modification method that can improve the stability of water-forming NADH oxidase derived from Streptococcus mutans by appropriately introducing mutation.