title: Acylpeptide hydrolase: inhibitors and some active site residues of the human enzyme.
abstract: Acylpeptide hydrolase may be involved in N-terminal deacetylation of nascent polypeptide chains and of bioactive peptides. The activity of this enzyme from human erythrocytes is sensitive to anions such as chloride, nitrate, and fluoride. Furthermore, blocked amino acids act as competitive inhibitors of the enzyme. Acetyl leucine chloromethyl ketone has been employed to identify one active site residue as His-707. Diisopropylfluorophosphate has been used to identify a second active site residue as Ser-587. Chemical modification studies with a water-soluble carbodiimide implicate a carboxyl group in catalytic activity. These results and the sequence around these active site residues, especially near Ser-587, suggest that acylpeptide hydrolase contains a catalytic triad. The presence of a cysteine residue in the vicinity of the active site is suggested by the inactivation of the enzyme by sulfhydryl-modifying agents and also by a low amount of modification by the peptide chloromethyl ketone inhibitor. Ebelactone A, an inhibitor of the formyl aminopeptidase, the bacterial counterpart of eukaryotic acylpeptide hydrolase, was found to be an effective inhibitor of this enzyme. These findings suggest that acylpeptidase hydrolase is a member of a family of enzymes with extremely diverse functions.
authors.affiliation: Universita La Sapienza, Dipartimento di Scienze Biochimiche A. Rossi-Fanelli, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Scaloni
authors.forename: W M
authors.initials: WM
authors.lastname: Jones
authors.forename: D
authors.initials: D
authors.lastname: Barra
authors.forename: M
authors.initials: M
authors.lastname: Pospischil
authors.forename: S
authors.initials: S
authors.lastname: Sassa
authors.forename: A
authors.initials: A
authors.lastname: Popowicz
authors.forename: L R
authors.initials: LR
authors.lastname: Manning
authors.forename: O
authors.initials: O
authors.lastname: Schneewind
authors.forename: J M
authors.initials: JM
authors.lastname: Manning
mesh_terms: D000107:Acetylation; D000590:Amino Acid Chloromethyl Ketones / Q000737:chemistry; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000494:pharmacology; D000626:Aminopeptidases / Q000037:antagonists & inhibitors* / Q000235:genetics; D000838:Anions; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001665:Binding Sites; D002234:Carbodiimides / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D002874:Chromosome Mapping; D002893:Chromosomes, Human, Pair 3; D004912:Erythrocytes / Q000201:enzymology; D006801:Humans; D007531:Isoflurophate / Q000737:chemistry; D007783:Lactones / Q000494:pharmacology; D008969:Molecular Sequence Data; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000235:genetics; D010449:Peptide Mapping; D011480:Protease Inhibitors / Q000494:pharmacology*; D012492:Salts / Q000494:pharmacology; D014357:Trypsin / Q000378:metabolism
chemical_list: D000590:Amino Acid Chloromethyl Ketones; D000596:Amino Acids; D000838:Anions; D000900:Anti-Bacterial Agents; D002234:Carbodiimides; D007783:Lactones; D011480:Protease Inhibitors; D012492:Salts; D007531:Isoflurophate; C026937:leucine chloromethyl ketone; C030794:ebelactone A; D010447:Peptide Hydrolases; D000626:Aminopeptidases; C038220:acylaminoacyl-peptidase; D014357:Trypsin