NO (nitric oxide) is a diffusible gas molecule produced intracellularly by three distinct nitric oxide synthase (NOS) enzymes that are highly conserved in mammalian species. The NOS enzymes are haemcontaining proteins that catalyse a fiveelectron oxidation process of the guanidino nitrogen of arginine and in the presence of O2. NOS activity is, in fact, a tandem of two consecutive reactions: a reductase step catalysed by a moiety of NOS homologous with the cytochrome P450 reductase, including the NADPH and flavin nucleotide cofactorbinding domains, and an oxygenase step coupling the reduction of Fe3+ to Fe2+ in the haem to the release of NO and citrulline from arginine and molecular oxygen. The reaction requires several cofactors, including tetrahydrobiopterin and calcium/calmodulin.
Skip Nav Destination
Feature| June 01 2012
Nitric oxide, vascular function and exercise
Lisardo Boscá ;
Biochem (Lond) (2012) 34 (3): 28–32.
- Views Icon Views
- PDF LinkPDF
- Share Icon Share
Lisardo Boscá, Antonio Castrillo; Nitric oxide, vascular function and exercise. Biochem (Lond) 1 June 2012; 34 (3): 28–32. doi: https://doi.org/10.1042/BIO03403028
Download citation file: