Get Role Of The Nitric-oxide Synthase Isoforms During -induced ... - Msjc

The inducible isoform, iNOS, involved in immune response, binds calmodulin at physiologically relevant concentrations, and produces NO as an immune defense mechanism, as NO is a free radical with an unpaired electron. It is the proximate cause of septic shock and may function in autoimmune disease.

eNOS and nNOS isoforms are activated at concentrations of calcium greater than 100 nM, while iNOS shows higher affinity for Ca2+/calmodulin (CALM2, CALM3, CALM1, P62158) with great avidity and is essentially calcium-independent and constitutively active.

Aside from its important role in the immune system, iNOS-derived NO may be hepatoprotective and may also play an important role in wound healing (by enhancing the synthesis of vascular endothelial growth factor and collagen).

NO is biologically generated by a family of three nitric oxide synthase enzymes (NOS) isoforms: neuronal nitric oxide synthase (nNOS or NOS1), inducible nitric oxide synthase (iNOS or NOS2), and endothelial nitric oxide synthase (eNOS or NOS3).

Nitric oxide synthases (EC 1.14. 13.39) (NOSs) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. NO is an important cellular signaling molecule. It helps modulate vascular tone, secretion, airway tone, and peristalsis, and is involved in angiogenesis and neural development.

There are three isoforms of nitric oxide synthase (NOS) named ing to their activity or the tissue type in which they were first described. The isoforms of NOS are neuronal NOS (or nNOS), endothelial NOS (or eNOS) and inducible NOS (or iNOS).

Nitric Oxide Synthase Genes Nitric oxide synthases (NOS) catalyze the 5-electron oxidation of l-arginine to produce l-citrulline and the free radical nitric oxide (NO) (1, 2). The NOS enzymes are best characterized as apoenzymes.

Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodilatation via peripheral nitrergic nerves.