NADPH Oxidases

A family of membrane-associated flavoprotein NADPH-dependent oxidoreductases that catalyze the univalent reduction of OXYGEN to create SUPEROXIDES. Structurally, they are characterized by six N-terminal transmembrane ALPHA-HELICES, a FLAVIN-ADENINE DINUCLEOTIDE (FAD)-binding region, and a C-terminal NADPH-binding region. They are expressed primarily by EPITHELIAL CELLS in gut, kidney, colon, and smooth muscle tissues, as well as GRANULOCYTES and function to transfer electrons across membranes to molecular oxygen. Defects in the production of superoxide ions by some NADPH oxidases result in GRANULOMATOUS DISEASE, CHRONIC.