Effect of guanosine nucleotides on the respiratory burst oxidase from human neutrophils.
The respiratory burst is a series of metabolic events which result in the production of microbicidal oxidants by phagocytes. The enzyme responsible for the respiratory burst is a membrane-bound oxidase which catalyzes the production of O-2 by the NADPH-dependent reduction of oxygen. Activity of this oxidase is diminished by a variety of guanosine-containing nucleotides. The decrease in activity caused by GTP, the most potent of these, occurs rapidly and is not solely dependent on hydrolysis of terminal phosphate groups. GTP appears to diminish oxidase activity through both inhibition and inactivation. GTP-mediated inhibition is kinetically mixed with respect to NADPH.
D006150:Guanine Nucleotides / Q000494:pharmacology*; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D009247:NADH, NADPH Oxidoreductases / Q000097:blood*; D019255:NADPH Oxidases; D009504:Neutrophils / Q000201:enzymology*; D010101:Oxygen Consumption / Q000187:drug effects*
D006150:Guanine Nucleotides; D006160:Guanosine Triphosphate; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases