Brain nitric oxide synthase (NOS), which utilizes NADPH and calcium/calmodulin as cofactors for metabolizing L-arginine to nitric oxide (NO) and L-citrulline, contains recognition sites for the flavins FAD and FMN. Using a spin-trapping technique combined with electron spin resonance spectroscopy, we report that brain NOS generates superoxide O-·2 in a calcium/calmodulin-dependent manner. The 'specific inhibitors' of NOS, N(G)- monomethyl L-arginine (L-NMMA), and N(G)-nitro-L-arginine methyl ester (L- NAME), have different effects on O-·2 generation. For L-NMMA, O-·2 production is unaffected, while for L-NAME, inhibition of this free radical is concentration-dependent.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Biological Chemistry|
|State||Published - 1992|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology