Studies of pyridine nucleotide oxidizing enzymes from human neutrophils.
An NADH cytochrome c reductase has been identified in plasma membrane fractions from neutrophils in addition to the superoxide producing NADPH oxidase which has been extensively studied by other investigators. Activation of neutrophils resulted in increased enzyme activities but to different degrees; the NADH cytochrome c reductase increased 2 fold in specific activity and the NADPH oxidase 30 fold. Treatment of the plasma membrane fraction with sonication and differential centrifugation yielded a particulate fraction (R2) with a 2 fold increase in specific activities of both enzymes and concentrations of cytochrome b and FAD. The cytochrome b in the preparation was not reduced under anaerobic conditions by either NADH or NADPH. Treatment of preparations of R2 with deoxycholate or potassium thiocyanate separated the two enzymes yielding particulate preparations with only NADPH oxidase or NADH cytochrome c reductase activity, respectively.
D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D003579:Cytochrome Reductases / Q000097:blood*; D003573:Cytochrome b Group / Q000097:blood; D005486:Flavin Mononucleotide / Q000097:blood*; D005182:Flavin-Adenine Dinucleotide / Q000097:blood*; D006801:Humans; D007700:Kinetics; D009097:Multienzyme Complexes / Q000097:blood*; D009245:NADH Dehydrogenase / Q000097:blood*; D009247:NADH, NADPH Oxidoreductases / Q000097:blood*; D019255:NADPH Oxidases; D009251:NADPH-Ferrihemoprotein Reductase / Q000097:blood*; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology*; D010084:Oxidation-Reduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D003573:Cytochrome b Group; D009097:Multienzyme Complexes; D005182:Flavin-Adenine Dinucleotide; D005486:Flavin Mononucleotide; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D003579:Cytochrome Reductases; D009251:NADPH-Ferrihemoprotein Reductase; D019255:NADPH Oxidases; D009245:NADH Dehydrogenase; D013755:Tetradecanoylphorbol Acetate