O-aminophenol oxidase

o-Aminophenol oxidase (, isophenoxazine synthase, o-aminophenol:O2 oxidoreductase, 2-aminophenol:O2 oxidoreductase, GriF) is an enzyme with systematic name 2-aminophenol:oxygen oxidoreductase. This enzyme catalyses the following chemical reaction


 * 2 o-aminophenol + O2 + acceptor 2-aminophenoxazin-3-one + reduced acceptor + 2 H2O (overall reaction)
 * (1a) 2 2-aminophenol + O2 2 6-iminocyclohexa-2,4-dienone + 2 H2O
 * (1b) 2 6-iminocyclohexa-2,4-dienone + acceptor 2-aminophenoxazin-3-one + reduced acceptor (spontaneous)

o-Aminophenol oxidase is a flavoprotein.