The Endogenous Metabolite Hypochlorite Activates Indoleamine 2,3-Dioxygenase-1 for Catalysis: Functional and Mechanistic Implications.
Indolamine 2,3-dioxygenase (IDO1) catalyzes the oxidative cleavage of l-tryptophan (l-Trp) to N'-formyl-l-kynurenine (l-NFK). The generally used in vitro assay for probing IDO1 activity relies on ascorbic acid and synthetic methylene blue to initiate the reaction by ferric iron reduction, with the endogenous activator...