Mechanism and regulation of ferrous heme-nitric oxide (NO) oxidation in NO synthases.

ABSTRACT: Nitric oxide (NO) synthases (NOSs) catalyze the formation of NO from l-arginine. We have shown previously that the NOS enzyme catalytic cycle involves a large number of reactions but can be characterized by a global model with three main rate-limiting steps. These are the rate of heme reduction by the flavin domain (k_r ), of dissociation of NO from the ferric heme-NO complex (k_d ), and of oxidation of the ferrous heme-NO complex (k_ox). The reaction of oxygen with the ferrous heme-NO species is part of a futile cycle that does not directly contribute to NO synthesis but allows a population of inactive enzyme molecules to return to the catalytic cycle, and thus, enables a steady-state NO synthesis rate. Previously, we have reported that t

SUBMITTER: Tejero J 

PROVIDER: S-EPMC6514623 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature