title: Purification and characterization of a novel thermostable lipase from Bacillus sp.
abstract: A thermostable lipase from Bacillus sp. has been purified to homogeneity as judged by disc-PAGE, SDS-PAGE, and isoelectric focusing. The purification included ammonium sulfate fractionation, treatment with acrinol, and sequential column chromatographies on DEAE-Sephadex A-50, Toyopearl HW-55F, and Butyl Toyopearl 650M. The purified enzyme was found to be a monomeric protein with Mr of 22,000, and pI of 5.1. The optimal pH at 30 degrees C, and optimal temperature at pH 5.6 were 5.5-7.2, and 60 degrees C, respectively, when olive oil was used as the substrate. The substrate specificity towards simple triglycerides was broad and 1- and 3-positioned ester bonds were hydrolyzed in preference to a 2-positioned ester bond. The addition of acetone to the assay mixture in the range of 0-60% (v/v) stimulated the enzyme remarkably, whereas n-hexane had an inhibitory effect.
authors.affiliation: Osaka Municipal Technical Research Institute.
authors.forename: A
authors.initials: A
authors.lastname: Sugihara
authors.forename: T
authors.initials: T
authors.lastname: Tani
authors.forename: Y
authors.initials: Y
authors.lastname: Tominaga
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000645:Ammonium Sulfate; D001407:Bacillus / Q000187:drug effects / Q000201:enzymology*; D002848:Chromatography, DEAE-Cellulose; D004795:Enzyme Stability; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007526:Isoelectric Point; D008049:Lipase / Q000737:chemistry / Q000302:isolation & purification*; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D008670:Metals; D008049:Lipase; D000645:Ammonium Sulfate