Phagocyte NADPH oxidase (NOX2)

The phagocyte NADPH oxidase, commonly known as the NOX2 complex, is a multi-subunit enzyme system primarily expressed in neutrophils, macrophages, and other phagocytic cells. Its fundamental biological role is the generation of superoxide anions by transferring electrons from NADPH to molecular oxygen, a process known as the 'respiratory burst' (StatPearls, PMID: 30020619). The active complex consists of a membrane-bound flavocytochrome b558 (comprising the gp91phox and p22phox subunits) and several cytosolic regulatory proteins including p47phox, p67phox, and p40phox, along with the small GTPase Rac (UniProt P04839). While it is indispensable for host defense against bacterial and fungal infections—demonstrated by the fact that genetic deficiencies lead to Chronic Granulomatous Disease (CGD)—pathological overactivation is a key driver of oxidative stress in chronic inflammatory conditions (PubMed, PMID: 28246317). Consequently, it is a major therapeutic target for treating atherosclerosis, neurodegenerative diseases like Parkinson's, and ischemia-reperfusion injury. Current drug development focuses on small-molecule inhibitors that can selectively modulate its activity without compromising the systemic immune response.

Other names

NADPH oxidase 2NOX2 complexCytochrome b-245Respiratory burst oxidasegp91phox complex

NADPH oxidase inhibition, Superoxide production inhibition, Disruption of subunit assembly (e.g., p47phox-p22phox interaction), Competitive inhibition of NADPH binding