title: Purification and properties of glucosyltransferase from Aureobasidium.
abstract: Purification and properties of glucosyltransferase, which produces panose (Glc alpha 1-->6Glc alpha 1-->4Glc) and isomaltose (Glc alpha 1-->6Glc) from maltose (Glc alpha 1-->4Glc), are reported. The enzyme, from Aureobasidium, was purified to homogeneity by fractionations involving ammonium sulfate and DEAE-Cellulofine, S-Sepharose Fast Flow and Sephadex G-200 chromatography. Molecular mass of the enzyme was estimated to be 395 kDa by gel filtration. The enzyme was identified as a glycoprotein which contains 32% (w/w) carbohydrate. The optimum pH for the enzymatic reaction was 4.5-5.5 and the enzyme was stable over a pH range of 4-6. The optimum reaction temperature for the enzyme was 65 degrees C and the enzyme retained more than 96% activity at 60 degrees C after 15 min. The enzyme produced panose from maltose by means of a high efficiency (45.5%) glucosyl-transfer reaction. The enzyme was inhibited by metal ions, such as those of mercury, silver and aluminum, and also by organic inhibitors, especially nitrilotriacetic acid.
authors.affiliation: Department of Materials Science, Faculty of Engineering, Miyazaki University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Hayashi
authors.forename: T
authors.initials: T
authors.lastname: Hayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Takasaki
authors.forename: K
authors.initials: K
authors.lastname: Imada
mesh_terms: D001709:Biotechnology; D002240:Carbohydrate Sequence; D004795:Enzyme Stability; D005936:Glucans / Q000096:biosynthesis / Q000737:chemistry; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007534:Isomaltose / Q000096:biosynthesis / Q000737:chemistry; D007700:Kinetics; D008320:Maltose / Q000737:chemistry / Q000378:metabolism; D003904:Mitosporic Fungi / Q000201:enzymology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013696:Temperature
chemical_list: D005936:Glucans; C008763:panose; D007534:Isomaltose; D008320:Maltose; D005964:Glucosyltransferases