Structural characterization of osmoregulator peptides from the brain of the leech Theromyzon tessulatum: IPEPYVWD and IPEPYVWD-amide.
Neurons immunoreactive to an antiserum (a-OT) directed specifically against the C-terminal part (prolyl-leucyl-glycinamide) of vertebrate oxytocin (OT) were detected in the brain of the leech Theromyzon tessulatum. With high pressure gel permeation chromatography followed by reversed-phase HPLC on brain extracts, evidence was given of the presence of three peptides (P1, P2, P3) immunoreactive to a-OT. Results of injection experiments in T. tessulatum and of titrations of each peptide at the different physiological stages of the animals which showed a peak in peptide P1 amount at stage 3B, indicated that P1 is the active OT-like peptide. Using three steps of reversed-phase HPLC, Edman degradation and electrospray mass spectrometry, two sequences for P1 (IPEPYVWD and IPEPYVWD-amide) were found. These peptides differ from peptides to the oxytocin/vasopressin family and are unique in the animal kingdom. Confirmation of their action on the hydric balance and their distribution in the CNS were presented.
Salzet
M
M
Centre de Biologie Cellulalaire, EA DRED 1027, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France. salzet@pop.univ.lille1.fr
Vandenbulcke
F
F
Verger-Bocquet
M
M
D000818:Animals; D001921:Brain / Q000378:metabolism / Q000648:ultrastructure*; D007150:Immunohistochemistry; D007865:Leeches; D008854:Microscopy, Electron; D009479:Neuropeptides / Q000378:metabolism*; D014882:Water-Electrolyte Balance
D009479:Neuropeptides