Cofactor Recycling Using a Thermostable NADH Oxidase

From the standpoint of enzymatic organic synthesis, NADH oxidase (NOX) will be a key enzyme that plays an essential role in the cofactor regeneration of NAD+ dependent enzymatic reactions. For example, enzymatic enantioselective oxidations of racemic secondary alcohols (Geueke et al., 2003; Riebel et al., 2003; Hummel & Riebel, 1996) and amino acids (Hummel et al., 2003a) have been reported as utilizing this enzyme (Fig. 1). The kinetic resolutions of secondary alcohols are important processes in cases where preparation of the corresponding ketones is difficult. In these reported reactions, NAD+ dependent enantioselective alcohol dehydrogenase (or amino acid dehydrogenase) was used with NOX for regeneration of the oxidized form of cofactor NAD+.