FMRFamide-related peptides in the sex segmental ganglia of the Pharyngobdellid leech Erpobdella octoculata. Identification and involvement in the control of hydric balance.
Using enzyme-linked immunosorbent assays, a dot-immunobinding assay and a three-step reverse-phase HPLC separation, four Arg-Phe-amide (RFamide) peptides were purified from sex segmental ganglia extracts of the leech Erpobdella octoculata; FMRFamide, FM(O)RFamide, FLRFamide and GDPFLRFamide. Their amino acid sequences were elucidated by means of a combined approach using antiserum specificity, synthetic-peptide coelution, automated Edman degradation and electrospray mass spectrometry. One of these peptides, GDPFLRFamide, is a novel leech RFamide neuropeptide. Two of the above RFamide peptides are involved in the control of leech hydric balance; one (GDPFLRFamide) is diuretic, the other (FMRFamide) is anti-diuretic. Titration of each purified RFamide peptide indicated a similar amount of each tetrapeptide and of tetrapeptides and heptapeptides. A comparison between RFamide peptides of E. octoculata and molluscs reveals structural similarities supporting the hypothesis for the existence of an ancestral RFamide peptide gene common to leeches and molluscs.
Salzet
M
M
Laboratoire de Biologie Animale, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France.
Bulet
P
P
Wattez
C
C
Malecha
J
J
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D017952:Ganglia, Invertebrate / Q000737:chemistry; D007865:Leeches / Q000737:chemistry* / Q000502:physiology; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000737:chemistry / Q000302:isolation & purification* / Q000502:physiology; D017421:Sequence Analysis; D014882:Water-Electrolyte Balance / Q000502:physiology
D009479:Neuropeptides; C058047:arginylphenylalaninamide