title: Purification and characterization of a new alpha-amylase of intermediate thermal stability from the yeast Lipomyces kononenkoae.
abstract: A new alpha-amylase from the extracellular culture of the yeast Lipomyces kononenkoae CBS 5608 has been purified to homogeneity by ammonium sulphate treatment, affinity binding on cross-linked starch, and DEAE-Biogel A chromatography. The enzyme was monomeric, with an apparent M(r) of 76 kilodaltons, pI < 3.5, and optimum pH 4.5-5.0, and exhibited intermediate thermal stability. The temperature for optimal enzyme activity was 70 degrees C. It is a glycoprotein with both N- and O-linked sugars. Kinetic analyses indicate that the enzyme has an endoamylolytic mechanism. The kM for soluble starch was 0.80 g.L-1 and the kcat was 622.s-1.
authors.affiliation: Deptamento Bioquímica, Facultad de Farmacia, Universidad de Barcelona, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Prieto
authors.forename: B R
authors.initials: BR
authors.lastname: Bort
authors.forename: J
authors.initials: J
authors.lastname: Martínez
authors.forename: F
authors.initials: F
authors.lastname: Randez-Gil
authors.forename: C
authors.initials: C
authors.lastname: Buesa
authors.forename: P
authors.initials: P
authors.lastname: Sanz
mesh_terms: D004795:Enzyme Stability; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D007700:Kinetics; D008970:Molecular Weight; D004718:Saccharomycetales / Q000201:enzymology*; D013213:Starch / Q000378:metabolism; D013696:Temperature; D000516:alpha-Amylases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D013213:Starch; D000516:alpha-Amylases