title: [Acid-stable and acid-unstable alpha-amylases of the mold fungi Aspergillus].
abstract: Acid-sable alpha-amylase of Asp. niger and acid-unstable, alpha-amylase of Asp. oryzae were studied. It was demonstrated, that beside being a more acid-stable properties, alpha-amylase Asp. niger has increased thermal stability as compared to alpha-amylase Asp. oryzae. The molecular weights of acid-stable alpha-amylase and acid-unstable alpha-amylase are 58 000 and 51 000, respectively. The amino acid composition, and the C- and N-terminal amino acids of both forms of alpha-amylases were determined. It was demonstrated, that the enzymes under study contain one sylfhydryl group per mole of enzyme, which in the Ca2+-bound form plays an important role in the maintenance of the catalytically active enzyme conformation.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000681:Amylases / Q000032:analysis*; D001230:Aspergillus / Q000201:enzymology*; D001234:Aspergillus niger / Q000201:enzymology; D001236:Aspergillus oryzae / Q000201:enzymology; D002118:Calcium / Q000378:metabolism; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D011487:Protein Conformation; D013438:Sulfhydryl Compounds / Q000032:analysis; D000516:alpha-Amylases / Q000032:analysis*
chemical_list: D000596:Amino Acids; D013438:Sulfhydryl Compounds; D000681:Amylases; D000516:alpha-Amylases; D002118:Calcium
vernacular_title: Kislotostabil'naia i kislotolabil'naia alf'a-amilazy plesnevykh gribov Aspergillus.