Ollivaux Céline, Gallois Dominique, Amiche Mohamed, Boscaméric Maryse, Soyez Daniel
Université Pierre et Marie Curie-Paris 06, UMR 7150 Mer et Santé, Equipe Physiologie Comparée des Erythrocytes, Station Biologique de Roscoff, France.
FEBS J. 2009 Sep;276(17):4790-802. doi: 10.1111/j.1742-4658.2009.07180.x. Epub 2009 Jul 31.
D-aminoacyl residues have been detected in various animal peptides from several taxa, especially vertebrates and arthropods. This unusual polymorphism was shown to occur in isoforms of the crustacean hyperglycaemic hormone (CHH) of the American lobster because a D-phenylalanyl residue was found in position 3 of the sequence (CHH and D-Phe3 CHH). In the present study, we report the detailed strategy used to characterize, in the lobster neuroendocrine system, isomers of another member of the CHH family, vitellogenesis inhibiting hormone (VIH). We have demonstrated that the fourth residue is either an L- or a D- tryptophanyl residue (VIH and D-Trp4 VIH). Furthermore, use of antisera specifically recognizing the epimers of CHH and VIH reveals that aminoacyl isomerization occurs in specialized cells of the X organ-sinus gland neurosecretory system and that the D-forms of the two neuropeptides are not only present in the same cells, but, importantly, also are co-packaged within the same secretory vesicles.
