Reaction Intermediates and Molecular Mechanism of Peroxynitrite Activation by NO Synthases.

ABSTRACT: The activation of the peroxynitrite anion (PN) by hemoproteins, which leads to its detoxification or, on the contrary to the enhancement of its cytotoxic activity, is a reaction of physiological importance that is still poorly understood. It has been known for some years that the reaction of hemoproteins, notably cytochrome P450, with PN leads to the buildup of an intermediate species with a Soret band at ∼435 nm (I435). The nature of this intermediate is, however, debated. On the one hand, I435 has been presented as a compound II species that can be photoactivated to compound I. A competing alternative involves the assignment of I435 to a ferric-nitrosyl species. Similar to cytochromes P450, the buildup of I435 occurs in nitric oxide synthases (NOSs) upon their reaction with excess PN. In

SUBMITTER: Lang J 

PROVIDER: S-EPMC5113124 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature