title: Dynorphin-derived peptides reveal the presence of a critical cysteine for the activity of brain endo-oligopeptidase A.
abstract: Brain endo-oligopeptidase A, a neuropeptide-metabolizing endopeptidase, has been considered a cysteine-endopeptidase because it is activated by thiols and inhibited by phydroxymercuribenzoate or 5,5'-dithiobis-(2-nitrobenzoic acid). The understanding of the unique specificity of endo-oligopeptidase A was useful for the synthesis of affinity labeling compounds containing as a thiol reactive group the Cys-(3-nitro-2-pyridinesulfenyl) group into dynorphin-derived peptides which are among the best substrates and competitive inhibitor of endopeptidase 22.19. Of the ten compounds tested, only peptides containing 8 to 13 amino acid residues caused irreversible inhibition. The fact that the most effective inhibitors had the reactive group either at the P'1 or at P'3 position [nomenclature of Schechter and Berger] would seem to argue that the reactive cysteine is in the vicinity of the active site, or actually involved in the catalytic step.
authors.affiliation: Department of Pharmacology, Institute of Biomedical Sciences, USP, São Paulo, Brazil.
authors.forename: M D
authors.initials: MD
authors.lastname: Gomes
authors.forename: L
authors.initials: L
authors.lastname: Juliano
authors.forename: E S
authors.initials: ES
authors.lastname: Ferro
authors.forename: R
authors.initials: R
authors.lastname: Matsueda
authors.forename: A C
authors.initials: AC
authors.lastname: Camargo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003545:Cysteine; D004399:Dynorphins / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008666:Metalloendopeptidases / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis / Q000494:pharmacology*; D010446:Peptide Fragments / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D009842:Oligopeptides; D010446:Peptide Fragments; D004399:Dynorphins; D008666:Metalloendopeptidases; C022510:thimet oligopeptidase; D003545:Cysteine