Phagocyte NADPH oxidase (NOX2, Cytochrome b-245 beta chain) (NOX2 (also known as gp91^phox^))

Phagocyte NADPH oxidase (NOX2) is a multi-component membrane-associated enzyme complex, most abundantly expressed in neutrophils and other phagocytes[1][2][3][5]. The active complex consists of membrane-bound subunits (NOX2/gp91^phox^ and p22^phox^) and cytosolic regulatory proteins (p47^phox^, p67^phox^, p40^phox^, and a Rac GTPase)[5]. Upon activation, electrons are transferred from cytosolic NADPH through flavin and heme cofactors to molecular oxygen, generating the superoxide anion (O~2~^−^), a precursor of other ROS[1][2][3][5][6][7]. These ROS play a central role in pathogen destruction during the respiratory burst of innate immune defense. Genetic defects in NOX2 cause chronic granulomatous disease, resulting in impaired microbial killing and heightened susceptibility to infection[2][3][5]. Dysregulation or excessive activation of NADPH oxidase leads to pathological inflammation and is implicated in cardiovascular, neurodegenerative, and oncological diseases[7]. Selective pharmacological inhibition remains challenging due to the complexity and ubiquity of NOX family enzymes.

Other names

NOX2gp91^phox^Cytochrome b-245 beta chainPhagocyte NADPH oxidaseCYBB (gene name)

Inhibition of electron transport from NADPH to oxygen, blocking superoxide formation Reduction of ROS generation and downstream inflammatory signaling Modulation of redox-dependent signaling pathways