title: Specificity of action on neuropeptides of an endopeptidase from the synaptosomal membranes of guinea pig brain.
abstract: An endopeptidase was solubilized and highly purified from the synaptosomal membrane fraction of guinea pig brain, and its specificity of action on various neuropeptides was investigated. It hydrolyzed specifically the Pro10-Tyr11 bond of neurotensin and showed a marked specificity toward Pro-X bonds present in the interior parts of various neuropeptides and related peptides. No cleavage, however, was observed at the first and second peptide bonds from the NH2-termini or from the COOH-termini of the peptides examined, suggesting that the enzyme requires both NH2- and COOH-terminal extentions of at least 3 residues from the scissile bond for its action. In addition, a limited number of other peptide bonds were cleaved, indicating that the enzyme is not strictly specific to Pro-X bonds. These results suggest the possible implication of this enzyme in the specific degradation of neurotensin and other peptide neurotransmitters in the synaptic cleft.
authors.affiliation: Department of Biophysics and Biochemistry, Faculty of Science, University of Tokyo.
authors.forename: S
authors.initials: S
authors.lastname: Yoshikawa
authors.forename: T
authors.initials: T
authors.lastname: Tashiro
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D006168:Guinea Pigs; D008566:Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000378:metabolism*; D013379:Substrate Specificity; D013574:Synaptosomes / Q000378:metabolism
chemical_list: D009479:Neuropeptides; D010450:Endopeptidases