Nicotinamide adenine dinucleotide phosphate oxidase family (NOX family)

The Nicotinamide adenine dinucleotide phosphate oxidase (NOX) family consists of seven transmembrane enzymes (NOX1-5, DUOX1-2) whose primary biological function is the deliberate generation of reactive oxygen species (ROS), such as superoxide and hydrogen peroxide (1.1.2, 1.4.3). Unlike other cellular sources where ROS are metabolic byproducts, NOX enzymes produce these molecules to serve as critical mediators in host defense, cell signaling, and vascular homeostasis (1.3.2, 1.4.5). The family is characterized by a conserved structure including six transmembrane domains and binding sites for NADPH and FAD (1.4.2, 1.4.3). Dysregulation or overactivation of specific NOX isoforms is strongly linked to the pathogenesis of chronic inflammatory conditions, cardiovascular diseases, neurodegeneration, and fibrotic disorders (1.2.2, 1.3.5). Conversely, a genetic deficiency in the NOX2 isoform leads to chronic granulomatous disease, an immunodeficiency characterized by the inability of phagocytes to kill pathogens (1.4.1, 1.4.4). Therapeutic development currently focuses on isoform-specific inhibitors, such as Setanaxib (GKT137831), which are being evaluated in clinical trials for diseases like primary biliary cholangitis and idiopathic pulmonary fibrosis to reduce pathological oxidative stress while preserving essential physiological signaling (1.2.2, 1.3.3).

Other names

NADPH oxidaseNOXDual oxidaseDUOXPhagocyte oxidasePHOXRespiratory burst oxidase

Inhibition of reactive oxygen species (ROS) production through competitive inhibition of NADPH binding, prevention of enzyme complex assembly (e.g., blocking p47phox translocation), or direct inhibition of the catalytic subunit activity.