title: Digestive amylase of a primitive animal, the scorpion: purification and biochemical characterization.
abstract: Scorpion, one of the most ancient invertebrates was chosen, as a model of a primitive animal, to purify and characterize an amylase located in the hepatopancreas. The scorpion digestive amylase (SDA) was purified. Pure SDA was obtained after heat treatment followed by ammonium sulfate fractionation and three steps of chromatography. The pure amylase is not glycosylated and has a molecular mass of 59,101 Da determined by MALDI-TOF MS analysis. The maximal amylase activity was measured at pH 7.0 and 50 degrees C, in the presence of Ca2+ and using potato starch as substrate. The enzyme was able to hydrolyze also, glycogen and amylose. The 23 NH2-terminal amino acid SDA residues were sequenced. The sequence obtained is similar to those of mammalian and avian pancreatic amylases. Nevertheless, polyclonal antibodies directed against SDA failed to recognize classical digestive amylases like the porcine pancreatic one.
authors.affiliation: Laboratoire de Biochimie et de Génie, Enzymatique des Lipases, ENIS route de Soukra, 1173 Sfax, Tunisia.
authors.forename: Hanen
authors.initials: H
authors.lastname: Louati
authors.forename: Nacim
authors.initials: N
authors.lastname: Zouari
authors.forename: Ahmed
authors.initials: A
authors.lastname: Fendri
authors.forename: Youssef
authors.initials: Y
authors.lastname: Gargouri
mesh_terms: D000595:Amino Acid Sequence; D000681:Amylases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004064:Digestive System / Q000187:drug effects / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007150:Immunohistochemistry; D007477:Ions; D008670:Metals / Q000494:pharmacology; D008969:Molecular Sequence Data; D012605:Scorpions / Q000201:enzymology*; D020539:Sequence Analysis, Protein; D013379:Substrate Specificity / Q000187:drug effects; D013696:Temperature
chemical_list: D007477:Ions; D008670:Metals; D000681:Amylases