title: Novel aminopeptidase specific for glycine from Actinomucor elegans.
abstract: Glycyl aminopeptidase was purified 600-fold from a cell extract of Actinomucor elegans by ammonium sulfate fractionation and sequential chromatography on DEAE-Toyopearl, Toyopearl HW65C, and FPLC-Superdex 200 HR, with recovery of 3.3% of the activity. The enzyme highly specifically hydrolyzed Gly-X (amino acid, peptide, or arylamide) bonds. The enzyme hydrolyzed other amino acid residues but at a rate of less than one fifth that with Gly. The order was Gly >> Ala >> Met > Arg > Ser > Leu. The Km value for glycyl-2-naphthylamide was 0.24 mM. The enzyme was most active at pH 8.0 with glycyl-2-naphthylamide as the substrate and its optimal temperature was 40 degrees C. The enzyme was inhibited by iodoacetic acid, and p-chloromercuribenzoate but not done by diisopropylfluorophosphate, o-phenanthroline, or EDTA. Magnesium and calcium had no effect on enzymic activity, but the activity was suppressed by cadmium, zinc, and copper ions. The molecular mass was estimated to be 320 kDa by gel filtration on FPLC-Superdex 200 HR and 56.5 kDa by SDS-PAGE, so the enzyme probably was a hexamer.
authors.affiliation: School of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ito
authors.forename: Xiaohang
authors.initials: X
authors.lastname: Ma
authors.forename: Nik
authors.initials: N
authors.lastname: Azmi
authors.forename: Hua-Shan
authors.initials: HS
authors.lastname: Huang
authors.forename: Mikio
authors.initials: M
authors.lastname: Fujii
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshimoto
mesh_terms: D000626:Aminopeptidases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D003470:Culture Media; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification; D005998:Glycine / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D009090:Mucorales / Q000378:metabolism*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D003470:Culture Media; D005656:Fungal Proteins; D000626:Aminopeptidases; C020824:glycyl aminopeptidase; D005998:Glycine