Galactose oxidase

Galactose oxidase (EC 1.1.3.9), a mononuclear Cu(I1) protein of the nonblue or type-2 classification,'-5 was first isolated in crude preparations by Cooper et al. in 1959.6 It appears to be one of a class of alcohol oxidases synthesized (and usually secreted) by a variety of fungal genera.' These enzymes include glucose oxidase, a flavoprotein, and other essentially uncharacterized proteins.'.' All catalyse the reaction: As a class, these enzymes exhibit a broad substrate specificity, e.g., primary and secondary, alkyl and aryl, other unsaturated alcohols can all be substrates for one or more of these enzymes. Galactose oxidase is the best characterized of this group largely because although a mononuclear Cu(I1) protein containing no other prosthetic group, it catalyses the 2-e-redox reaction at the substrate level using 0, as noted above. How the enzyme catalyses this reaction is a chemically fundamental and challenging question.