Pyruvate oxidase (pyruvate: cytochrome b 1 oxidoreductase, EC 18.104.22.168) is a peripheral membrane enzyme isolated from Escherichia coli which catalyzes the oxidative decarboxylation of pyruvate to yield acetate plus CO2. This enzyme is water-soluble and is removed from the bacteria by sonic oscillation. Relatively large quantities of the oxidase can be purified to homogeneity, and it is reasonably stable. Thiamine pyrophosphate (TPP) and flavin adenine dinucleotide (FAD) are known cofactors. The reduced enzyme (FADH2) can be coupled to a crude membranous particulate fraction from E. coli containing an electron transport chain in which oxygen is the terminal electron acceptor. Thus, either CO2 release or O2 consumption may be used to assay for oxidase activity in this system. The reduced enzyme will also directly reduce the dye 2,6-dichloroindophenol (DCIP), or ferricyanide, providing convenient spectrophotometric assays.
KeywordsBiological Chemistry Flavin Adenine Dinucleotide Trypsin Activation Crude Lipid Flavin Adenine Dinucleotide
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- Sweeney, E. W., 1961, M.S. Dissertation, University of Illinois.Google Scholar