title: Purification and characterization of amylases from small abalone (Sulculus diversicolor aquatilis).
abstract: Amylases II-1 and II-2 with molecular weights of 55.7 and 65 kDa, respectively, were purified to electrophoretical homogeneity from small abalone (Sulculus diversicolor aquatilis) by ammonium sulfate fractionation, Sepharose CL-6B, CM-Sepharose CL-6B, and Sephacryl S-100 chromatographs. They had optimal temperatures of 45 and 50 degrees C and an optimal pH of 6.0. The purified amylases were stable at pH 5.0-8.0 and 6.0-8.0, respectively. They were completely or partially inhibited by Hg(2+), Cu(2+), Cd(2+), Zn(2+), iodoacetamide, phenylmethanesulfonyl fluoride, and N-ethylmaleimide, suggesting the existence of cysteine at their active sites. Digestion tests against various polysaccharides suggested that the purified amylases II-1 and II-2 are neoamylases which can hydrolyze both alpha-1,4 and alpha-1,6 glucosidic bonds. Amylase II-2 might be an exo- and II-1 an endo-/exo-amylase.
authors.affiliation: Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan 202, Republic of China.
authors.forename: Ching-Yu
authors.initials: CY
authors.lastname: Tsao
authors.forename: Yun-Zu
authors.initials: YZ
authors.lastname: Pan
authors.forename: Shann-Tzong
authors.initials: ST
authors.lastname: Jiang
mesh_terms: D000681:Amylases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D000687:Amylopectin / Q000378:metabolism; D000818:Animals; D002845:Chromatography; D002855:Chromatography, Thin Layer; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008670:Metals / Q000494:pharmacology; D008970:Molecular Weight; D008974:Mollusca / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004791:Enzyme Inhibitors; D008670:Metals; D000687:Amylopectin; D000681:Amylases