The superoxide-generating NADPH oxidase of human neutrophils is electrogenic and associated with an H+ channel.
The membrane potential of cytoplasts, derived from human neutrophils, was depolarized by the activation of the superoxide-generating NADPH-dependent oxidase. The extent of the depolarization was inhibited by diphenylene iodonium and was therefore due directly to the activity of the oxidase, which must be electrogenic. The extent of the depolarization was influenced by alteration of the delta pH across the cytoplast membrane, indicating that the outward translocation of H+ eventually compensates for superoxide generation. The depolarization of the potential is enhanced by Cd2+, a blocker of H+ currents, suggesting that the compensatory movement is via an H+ channel.
Henderson
L M
LM
Department of Biochemistry, Medical School, University of Bristol, U.K.
Chappell
J B
JB
Jones
O T
OT
D001692:Biological Transport / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008564:Membrane Potentials; D009247:NADH, NADPH Oxidoreductases / Q000097:blood*; D019255:NADPH Oxidases; D009504:Neutrophils / Q000378:metabolism*; D009861:Onium Compounds / Q000494:pharmacology; D011522:Protons; D013481:Superoxides / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D009861:Onium Compounds; D011522:Protons; D013481:Superoxides; C007517:diphenyleneiodonium; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; C022709:superoxide-forming enzyme; D013755:Tetradecanoylphorbol Acetate