title: Structure-activity relations of the molluscan neuropeptide FMRFamide on some molluscan muscles.
abstract: Analogs of the molluscan neuropeptide FMRFamide were tested on four different molluscan muscle preparations which show qualitatively different responses to the peptide; the structure-activity relations are basically similar, but not identical. The C-terminal amide and the Arg3 residue are critical for FMRFamide-like activity on all four preparations. In contrast, analogs extended at the N-terminal or with conservative substitutions for the Phe1 or Met2 residue are approximately equipotent to FMRFamide. These structural requirements parallel those for the C-terminal tetrapeptide amide of gastrin.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D019835:FMRFamide; D006321:Heart / Q000187:drug effects; D008974:Mollusca; D009132:Muscles / Q000187:drug effects*; D009842:Oligopeptides / Q000494:pharmacology*; D013329:Structure-Activity Relationship
chemical_list: D009842:Oligopeptides; D019835:FMRFamide