Structural Characterization of a Diuretic Peptide from the Central Nervous System of the Leech Erpobdella octoculata
ANGIOTENSIN II AMIDE (*)
- Michel Salzet(1)(§),
- Philippe Bulet(2),
- Christian Wattez(1),
- Martine Verger-Bocquet(1) and
- Jean Malecha(1)
- From the (1)Laboratoire de Phylogénie moléculaire des Annélides ER 87 CNRS, Groupe de Neuroendocrinologie des Hirudinées, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d'Ascq Cédex, France and the
- (2)Institut de Biologie moléculaire et cellulaire, UPR 9022 CNRS, 15 rue Descartes, F-67084 Strasbourg Cédex, France
- § To whom correspondence should be addressed: Laboratoire de Phylogénie moléculaire des Annélides ER 87 CNRS, Groupe de Neuroendocrinologie des Hirudinées, Université des Sciences et Technologies de Lille, SN3, F-59655 Villeneuve d'Ascq Cédex, France . Tel: 33-2043-4054; Fax: 33-2043-6849.
Abstract
Purification of a material immunoreactive to an antiserum against angiotensin II and present in the central nervous system of the pharyngobdellid leech Erpobdella octoculata was performed by reversed-phase high pressure liquid chromatography combined with both enzyme-linked immunosorbent assay and dot immunobinding assays for angiotensin II. Establishment of the amino acid sequence by Edman degradation, electrospray, and fast atom bombardement mass spectrometry measurements and enzymatic treatment by carboxypeptidase A indicated that this “central” angiotensin II-like material, the first one fully characterized in the animal kingdom, is an angiotensin II amide. This finding constitutes also the first biochemical characterization of a peptide of the angiotensin family in an invertebrate. Synthetic angiotensin II amide exerts, when injected in leeches, a diuretic effect and is, 1 and 2 h postinjection, 100-fold more potent than vertebrate angiotensin II.
An identification of the proteins immunoreactive to an antiserum against angiotensin II performed at the level of both central
nervous system extracts and in vitro central nervous system-translated RNA products indicated that in the two cases, two proteins were detected. Their molecular
masses, which were, respectively, 
14 and 
18 kDa for the central nervous system extracts and 
15 and 
19 kDa for in vitro central nervous system-translated RNA products, differ from that of angiotensinogen (
60 kDa), the precursor of vertebrate angiotensin II.
Footnotes
-
↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
-
↵1 The abbreviations used are:
- RAS
-
renin-angiotensin system
- AI
-
angiotensin I
- A0
-
angiotensinogen
- AII
-
angiotensin II
- HPLC
-
high pressure liquid chromatography
- CNS
-
central nervous system
- DIA
-
dot immunobinding assay
- ELISA
-
enzyme-linked immunosorbent assay
- PTH
-
phenylthiohydantoin
- ESMS
-
electrospray mass spectrometry
- FABMS
-
fast atom bombardment mass spectrometry
- TBS
-
Tris-buffered saline
- HPGPC
-
high performance gel permeation chromatography
- PBS
-
phosphate-buffered saline.
-
↵2 M. Salzet, P. Bulet, C. Wattez, M. Verger-Bocquet, and J. Malecha, unpublished data.
-
- Received April 18, 1994.
- Revision received October 21, 1994.
- © 1995 by The American Society for Biochemistry and Molecular Biology, Inc.
