Isolation, structural characterization and biological function of a lysine-conopressin in the central nervous system of the pharyngobdellid leech Erpobdella octoculata.
Several neuropeptides are suspected to act on the control of hydric balance in leeches. One of these peptides, a peptide immunoreactive to an antibody against oxytocin, was previously characterized from the central nervous system of the leech Erpobdella octoculata [Salzet, M., Wattez, C., Verger-Bocquet, M., Beauvillain, J.-C. & Malecha, J. (1993) Brain Res. 601, 173-184]. This paper reports the isolation from the central nervous system of E. octoculata of another peptide of the oxytocin/vasopressin family; a lysine-vasopressin-like molecule. Its purification was performed by reverse-phase high-performance liquid chromatography combined with both dot immunobinding assay and enzyme-linked immunosorbent assay for lysine-vasopressin. The amino acid sequence was established by Edman degradation and confirmed by electrospray-mass-spectrometry measurement. The nonapeptide obtained corresponded to the lysine-conopressin previously isolated from the venom of the mollusc Conus geographus [Cruz, L. L., de Santos, V., Zafaralla, G. C., Ramilo, C. A., Zeikus, R., Gray, W. R. & Olivera, B. M. (1987) J. Biol. Chem. 262, 15821-15824]. In leeches, synthetic lysine-conopressin exerts a diuretic effect which can be compared to that of the arginine-vasopressin-like peptide isolated in the Insect Locusta migratoria [Proux, J., Miller, C. A., Li, J. P., Carney, R. L., Girardie, A., Delaage, M. & Schooley, D. A. (1987) Biochem. Biophys. Res. Commun. 149, 180-186].
Salzet
M
M
Laboratoire de Phylogénie moléculaire des Annélides, ERS 20 CNRS, Université des Sciences et Technologies de Lille, Villeneuve d'Ascq, France.
Bulet
P
P
Van Dorsselaer
A
A
Malecha
J
J
D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D007865:Leeches / Q000737:chemistry*; D008236:Lypressin / Q000737:chemistry; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism
D009842:Oligopeptides; C076621:conopressin G; D010121:Oxytocin; D008236:Lypressin