eNOS (Tyr-657)/nNOS (Tyr-895), phospho-specific polyclonal, anti-human, mouse, rat

Background:
Nitric oxide (NO) has a broad range of biological activities and is implicated in signaling pathways in phylogenetically diverse species. Nitric oxide synthases (NOS), the enzymes responsible for synthesis of NO, are homodimers whose monomers are themselves two fused enzymes: a cytochrome reductase and a cytochrome that requires three cosubstrates (L-arginine, NADPH, and oxygen) and five cofactors or prosthetic groups (FAD, FMN, calmodulin, tetrahydrobiopterin, and heme). Several distinct NOS isoforms are produced from three distinct genes, inducible NOS (iNOS, NOS-II), neuronal NOS (bNOS, NOS-I), and endothelial NOS (eNOS, ecNOS, NOS-III). Regulation of eNOS activity occurs through phosphorylation at multiple sites. Phosphorylation of Ser-633 (mouse Ser-632) in the FMN binding domain increases eNOS activity and may be important for the maintenance of NO synthesis after initial activation by Ca2+ flux and Ser-1177 phosphorylation. Tyr-657 is phosphorylated by PYK2 in response to fluid shear stress and this phosphorylation leads to attenuation of enzyme activity.

Immunogen: Phospho-eNOS (Tyr-657) synthetic peptide (coupled to carrier protein) corresponding to amino acids surrounding tyrosine 657 in human eNOS. This sequence is conserved in mouse (Tyr-656) and rat (Tyr-656) eNOS, and is identical to the conserved site in nNOS (Tyr-895). The site is also well conserved in iNOS (Tyr-631).

Specificity: The antibody detects a 140 kDa* band on SDS-PAGE immunoblots of human umbilical vein endothelial cells treated with pervanadate, and this reactivity is not observed after akaline phosphatase treatment.

Buffer/Storage:
Rabbit polyclonal, affinity-purified antibody is supplied in 100µl phosphate-buffered saline, 50% glycerol, 1 mg/ml BSA, and 0.05% sodium azide. Store at –20°C. Stable for 1 year.