superoxide-generating NAD(P)H oxidase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: NAD(P)H + O2 = NAD(P)H + O2-. [GOC:ai, PMID:10806195]

Superoxide-generating NAD(P)H oxidase activity is a crucial molecular function that catalyzes the production of superoxide radicals (O2-) from molecular oxygen (O2) using NADH or NADPH as electron donors. This process involves the transfer of electrons from NAD(P)H to molecular oxygen, with the subsequent generation of superoxide. This enzymatic activity is primarily associated with a family of transmembrane enzymes known as NADPH oxidases (NOXs), which are found in various cell types and play critical roles in diverse physiological and pathological processes.

The core catalytic unit of NOXs comprises a flavin adenine dinucleotide (FAD) binding site and a heme-binding site. The electron transfer pathway involves the sequential reduction of FAD and heme by NAD(P)H, followed by the transfer of an electron to molecular oxygen, resulting in the formation of superoxide. This superoxide production is tightly regulated by various factors, including intracellular signaling pathways, protein-protein interactions, and cellular redox status.

Superoxide generated by NAD(P)H oxidases has a wide range of downstream effects, participating in various signaling pathways and contributing to cellular processes such as inflammation, host defense, and wound healing. It also plays a role in various pathologies, including cardiovascular disease, cancer, and neurodegenerative disorders. For example, in immune cells, NOXs contribute to the generation of reactive oxygen species (ROS), which are essential for pathogen killing and inflammation. In vascular smooth muscle cells, NOXs contribute to vasoconstriction and vascular remodeling. Moreover, NOXs are implicated in the pathogenesis of several chronic diseases, such as atherosclerosis and hypertension.

In summary, superoxide-generating NAD(P)H oxidase activity is a critical enzyme function involved in diverse cellular processes by producing superoxide radicals. This activity is tightly regulated and plays essential roles in both physiological and pathological processes, impacting various aspects of cellular signaling, host defense, and disease pathogenesis.'
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Proteins (2)

Compounds (26)