PMID: 6985891Jan 25, 1980Paper

Studies on the quaternary structure of Escherichia coli pyruvate oxidase.

The Journal of Biological Chemistry
D J Stevens, R B Gennis

Abstract

Pyruvate oxidase is a peripheral membrane enzyme isolated from Escherichia coli. The enzyme catalyzes the oxidative decarboxylation of pyruvate to yield acetate plus CO2. The specific activity of the purified oxidase is stimulated 25-fold by lipids, and this lipid requirement has been the subject of previous studies. Since the enzyme is a tetramer at high protein concentrations (1 mg/ml) and is known to self-aggregate under certain conditions, the question arose as to whether the lipid stimulation observed in the steady state assay might be due to a change in the quaternary structure of the protein, either a dissociation or further association. This report is directed at determining the state of association of pyruvate oxidase under assay conditions by using fluorescence polarization. A photoreactive, nonspecific probe, 1-azidonaphthalene 5-sulfonate, was used to label the protein surface with an extrinsic fluorophore. It is concluded that under steady state assay conditions the oxidase remains tetrameric.

Related Concepts

Related Feeds

ASBMB Publications

The American Society for Biochemistry and Molecular Biology (ASBMB) includes the Journal of Biological Chemistry, Molecular & Cellular Proteomics, and the Journal of Lipid Research. Discover the latest research from ASBMB here.