title: Structure-activity relationships of neuromedin U. I. Contractile activity of dog neuromedin U-related peptides on isolated chicken crop smooth muscle.
abstract: Synthetic dog neuromedin U-25(d-NMU-25), U-8(d-NMU-8) and their fragments wer examined for contractile activity on chicken crop smooth muscle preparation. The relative activities of d-NMU-25, d-NMU-25(15--25)NH2 and d-NMU-8 to porcine neuromedin U-8 (p-NMU-8) were 1.69, 2.54 and 5.78, respectively. High activity of d-NMU-8 may be attributable to the N-terminal pGlu residue, which provides resistance to aminopeptidases. Various NMU-8 analogs, having various amino acids, N alpha-acetylated amino acids, D-amino acids, or simple organic acids at position 1, were synthesized and evaluated for contractile activity. None of the substitutions caused a significant decrease of the biological activity. Modification at the N-terminal to give aminopeptidase resistance produced analogs with increased contractile activity, presumably because they were not degraded by soluble enzymes released into the bioassay fluid from isolated chicken crop tissue.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokuriku University, Kanazawa, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Sakura
authors.forename: K
authors.initials: K
authors.lastname: Kurosawa
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D003426:Crop, Avian / Q000187:drug effects / Q000502:physiology; D004285:Dogs; D066298:In Vitro Techniques; D007700:Kinetics; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D009479:Neuropeptides / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology*; D010446:Peptide Fragments / Q000138:chemical synthesis* / Q000378:metabolism / Q000494:pharmacology*; D010447:Peptide Hydrolases / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013552:Swine
chemical_list: D009479:Neuropeptides; D010446:Peptide Fragments; C056900:neuromedin U; C046270:neuromedin U 8; C046271:neuromedin U 25; D010447:Peptide Hydrolases