Oxidation of reduced pyridine nucleotides by plasma membranes of soybean hypocotyl.
Highly purified plasma membranes isolated from soybean hypocotyls by free-flow electrophoresis or by a two-phase polymer separation system oxidize reduced pyridine nucleotides, NADH or NADPH, at rates of 2-5 nanomoles/mg protein/min. These rates are not influenced by mitochondrial inhibitors or by inhibitors of the alternate respiratory pathway. The NADH oxidase has a Km of 200 microM NADH. The enzyme activity is stimulated by Ca2+ and Mg2+ ions. The function of this enzyme is unknown at present, but it may represent a redox-controlled proton pump linked to acidification.
D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D006912:Hydroxyquinolines / Q000494:pharmacology; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D009097:Multienzyme Complexes / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D009249:NADP / Q000378:metabolism*; D019255:NADPH Oxidases; D010084:Oxidation-Reduction; D010944:Plants / Q000201:enzymology*; D012402:Rotenone / Q000494:pharmacology; D013025:Glycine max
D006912:Hydroxyquinolines; D009097:Multienzyme Complexes; D012402:Rotenone; D009243:NAD; C001333:2-(n-heptyl)-4-hydroxyquinoline N-oxide; D009249:NADP; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D008274:Magnesium; D002118:Calcium