title: Isolation and partial characterization of five myotropic peptides present in head extracts of the cockroach Leucophaea maderae.
abstract: Five peptides were isolated by reverse-phase HPLC from head extracts of the cockroach Leucophaea maderae. Four of the peptides were inactivated by aminopeptidase M (APM). The inability of APM to digest the fifth peptide suggests a blocked NH2-terminus. Four of the peptides were inactivated by carboxypeptidase Y (CPY). The activity of the fraction which would have contained proctolin was decreased by about 20%. The complete deactivation of proctolin by CPY indicated that a second peptide, co-eluting with proctolin but refractory to CPY digestion, was responsible for 80% of the biological activity in that fraction. Concentrations of the peptides necessary to produce a threshold response from the isolated cockroach hindgut ranged from 0.009 to 0.083 head equivalents/ml.
mesh_terms: D000626:Aminopeptidases / Q000378:metabolism; D000818:Animals; D018826:CD13 Antigens; D002268:Carboxypeptidases / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003058:Cockroaches / Q000032:analysis*; D004800:Enzymes, Immobilized / Q000378:metabolism; D005260:Female; D006257:Head / Q000032:analysis; D006358:Hot Temperature; D007422:Intestines / Q000187:drug effects; D008297:Male; D009479:Neuropeptides; D009842:Oligopeptides / Q000378:metabolism; D010455:Peptides / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology; D011489:Protein Denaturation; D013268:Stimulation, Chemical
chemical_list: D004800:Enzymes, Immobilized; D009479:Neuropeptides; D009842:Oligopeptides; D010455:Peptides; C011536:proctolin; D002268:Carboxypeptidases; D000626:Aminopeptidases; D018826:CD13 Antigens; C022633:serine carboxypeptidase