title: Quasi-elastic light scattering studies on pyruvate oxidase.
abstract: Quasi-elastic or dynamic light scattering has been used to examine the translational diffusion properties of the enzyme pyruvate oxidase (pyruvate: ferricytochrome beta 1 oxidoreductase, EC 1.2.2.2.). Controlled proteolysis of the enzyme converts the native form of the enzyme to a protease-activated form which has a specific activity about 20-fold greater than the native oxidase. Light scattering studies indicate no significant change in the size or shape of pyruvate oxidase as a result of this proteolytic activation. In both cases the enzyme may be characterized as a hydrated sphere with a Stokes radius of about 53A. The sedimentation velocity-diffusion technique was used to obtain the molecular weight of this tetrameric enzyme, about 252 000 with a value of f/f0 of 1.25.
mesh_terms: D002499:Centrifugation, Density Gradient; D004789:Enzyme Activation; D004926:Escherichia coli / Q000201:enzymology; D008968:Molecular Conformation; D008970:Molecular Weight; D011771:Pyruvate Oxidase / Q000378:metabolism; D013053:Spectrophotometry; D014357:Trypsin / Q000494:pharmacology
chemical_list: D011771:Pyruvate Oxidase; D014357:Trypsin