title: Purification and characterization of an intracellular beta-glucosidase from a Candida sake strain isolated from fruit juices.
abstract: A yeast strain isolated in the laboratory from fruit juices was studied and classified as Candida sake. The strain produces an intracellular beta-glucosidase when grown with cellobiose as the carbon source. The enzyme was purified by ion-exchange chromatography and gel filtration. The molecular mass of the purified intracellular beta-glucosidase, estimated by gel filtration, was 240 kDa. The tetrameric structure of the beta-glucosidase was determined following treatment of the purified enzyme with sodium dodecyl sulfate. The enzyme exhibited optimum activity at 52 degrees C and pH 4.25 with citrate-phosphate buffer. The enzyme was active against soluble glycosides with the (1-->4)-beta configuration, and from Lineweaver Burk plots, a Km value of 6.9 mmol/L was found for p-nitrophenyl-beta-D-glucopyranoside. The beta-glucosidase was found to be tolerant to glucose inhibition with a Ki value of 0.2 mol/L.
authors.affiliation: IFREMER Centre de Brest, DRV/VP Laboratoire de Biotechnologie, Plouzané, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Gueguen
authors.forename: P
authors.initials: P
authors.lastname: Chemardin
authors.forename: A
authors.initials: A
authors.lastname: Arnaud
mesh_terms: D002175:Candida / Q000201:enzymology*; D002845:Chromatography; D005638:Fruit / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D008670:Metals / Q000378:metabolism; D008970:Molecular Weight; D013379:Substrate Specificity; D013696:Temperature; D001617:beta-Glucosidase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D008670:Metals; D001617:beta-Glucosidase