title: Purification and properties of two lactose hydrolases from Trichosporon cutaneum.
abstract: Two enzymes that hydrolysed lactose were purified essentially to homogeneity from cell extracts of the oleaginous yeast Trichosporon cutaneum. One enzyme of Mr 120,000 had properties typical of a beta-galactosidase (EC 3.2.1.23). It hydrolysed lactose, lactulose and nitrophenyl-beta-D-galactosides. The enzyme required K+ or Rb+ for activity, and other monovalent cations tested were not effective. Enzyme activity was abolished by EDTA and stimulated by Mg2+, Mn2+ and Ca2+. The beta-galactosidase was induced by lactose, galactose, lactulose and lactobionic acid. The other enzyme, a beta-glycosidase (EC 3.2.1.21) of Mr 52,000 showed no ionic requirements and it hydrolysed lactose, nitrophenyl-beta-D-galactosides, 4-nitrophenyl-beta-D-glucoside, cellobiose, laminaribiose, laminaritriose and sophorose, but not gentiobiose, 4-nitrophenyl-beta-D-mannoside or sucrose. This enzyme was induced by lactose, galactose and lactulose, and also by cellobiose.
authors: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors: M
authors: M
authors: West
authors: G W
authors: GW
authors: Emerson
authors: P A
authors: PA
authors: Sullivan
mesh_terms: D002412:Cations / Q000494:pharmacology; D002848:Chromatography, DEAE-Cellulose; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D007785:Lactose / Q000378:metabolism*; D008970:Molecular Weight; D013379:Substrate Specificity; D014250:Trichosporon / Q000187:drug effects / Q000201:enzymology*; D001616:beta-Galactosidase / Q000737:chemistry / Q000378:metabolism*
chemical_list: D002412:Cations; D006026:Glycoside Hydrolases; D001616:beta-Galactosidase; D007785:Lactose