Solubilization, Purification and Properties of Membrane-bound Glycerol Dehydrogenase from Gluconobacter industrius

Abstract

Membrane-bound glycerol dehydrogenase was solubilized and purified about 100-fold from the membrane of Gluconobacter industrius IFO 3260 grown on a glycerol-glutamate medium. Solubilization of the enzyme was successfully achieved by use of 0.5% dimethyldodecylamineoxide in 0.05 M Tris-HCl, pH 8.0. Alcohol dehydrogenase and d-glucose dehydrogenase, which were abundantly formed in the same bacterial membrane, were eliminated on solubilization. Glycerol dehydrogenase was further purified through fractionation with polyethylene glycol 6000. The enzyme showed a broad substrate specificity and various kinds of polyhydroxyl alcohols, in addition to glycerol, were rapidly oxidized in the presence of 2,6-dichlorophenolindophenol and phenazine methosulfate as the electron acceptor but NAD and NADP were inert. The enzyme was proved to be a quinoprotein in which pyrroloquinoline quinone functioned as the prosthetic group.