Nitric oxide synthase 1 (nNOS) (nNOS)

Nitric oxide synthase 1 (nNOS) is a constitutive, calcium-dependent enzyme primarily expressed in the central and peripheral nervous systems, where it catalyzes the synthesis of nitric oxide (NO) from L-arginine [1, 6]. In the rat and other mammals, nNOS-derived NO acts as a critical signaling molecule involved in neurotransmission, synaptic plasticity, and the regulation of smooth muscle relaxation [4, 5]. While physiological levels of NO are essential for learning and memory, its overproduction is a major contributor to neurotoxicity and oxidative stress [1, 2]. Pathological nNOS activity is implicated in a wide range of conditions, including stroke, neuropathic pain, and neurodegenerative diseases such as Parkinson's and Alzheimer's [2, 20]. Consequently, nNOS is a significant therapeutic target, with research focused on developing selective inhibitors that can cross the blood-brain barrier [1, 2]. A primary challenge in drug development is achieving high selectivity for nNOS over the endothelial (eNOS) and inducible (iNOS) isoforms to prevent adverse cardiovascular and immune effects [2, 21].

Other names

Neuronal nitric oxide synthaseNOS1bNOSNitric oxide synthase, brainNOS type IConstitutive NOSNC-NOSPeptidyl-cysteine S-nitrosylase NOS1

Competitive inhibition of the conversion of L-arginine to nitric oxide and L-citrulline, typically by binding to the heme or arginine binding sites, or by antagonizing tetrahydrobiopterin (BH4) binding.