Kinetic Properties of Galactose Oxidase from Gibberella fujikuroi

抄録

The kinetic properties of galactose oxidase of Gibberella fujikuroi were investigated. The enzyme oxidized D-galactose, 2-substituted D-galactoses, 2-epimer D-talose, and D-galactosecontaining oligosaccharides, but not other saccharides. The enzyme was highly specific for molecular oxygen as an electron acceptor. The enzymegave a nonlinear Lineweaver-Burk plot when the oxidation rate at a variety of galactose concentrations was investigated. The data were well explained by the assumption that the enzyme has two binding sites for galactose. K₁ and K₂, which are the dissociation constants for the first and second bindings of galactose to the enzyme, were calculated to be 1.3mM and 42mM, respectively. The 'enzyme was mixedly inhibited by dgalacturonic acid.