Superoxide induces endothelial nitric-oxide synthase protein thiyl radical formation, a novel mechanism regulating eNOS function and coupling.

ABSTRACT: An increase in production of reactive oxygen species resulting in a decrease in nitric oxide bioavailability in the endothelium contributes to many cardiovascular diseases, and these reactive oxygen species can oxidize cellular macromolecules. Protein thiols are critical reducing equivalents that maintain cellular redox state and are primary targets for oxidative modification. We demonstrate endothelial NOS (eNOS) oxidant-induced protein thiyl radical formation from tetrahydrobiopterin-free enzyme or following exposure to exogenous superoxide using immunoblotting, immunostaining, and mass spectrometry. Spin trapping with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) followed by immunoblotting using an anti-DMPO antibody demonstrated the formation of eNOS protein radicals, which were abolished by

SUBMITTER: Chen CA 

PROVIDER: S-EPMC3190717 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature