Characterization of a NADH:Dichloroindophenol Oxidoreductase from Bacillus subtilis

Abstract

We expressed and purified an azoreductase homolog, YvaB, from Bacillus subtilis. YvaB was found to have NADH:2,6-dichloroindophenol oxidoreductase activity, as well as azoreductase activity. Purified YvaB was active without FMN, unlike Escherichia coli azoreductase. YvaB was most active at pH 7.5 and 40 °C, and was stable up to 55 °C after incubation for 30 min. Remarkably, it was stable in the presence of Ag⁺, and was activated by the addition of non-ionic detergents. Other enzymatic properties of YvaB were also investigated.