title: Isolation of L-3-phenyllactyl-Leu-Arg-Asn-NH2 (Antho-RNamide), a sea anemone neuropeptide containing an unusual amino-terminal blocking group.
abstract: Using a radioimmunoassay for the carboxyl-terminal sequence Arg-Asn-NH2, we have purified a peptide from acetic acid extracts of the sea anemone Anthopleura elegantissima. By classical amino acid analyses, mass spectrometry, and 1H NMR spectroscopy, the structure of this peptide was determined as 3-phenyllactyl-Leu-Arg-Asn-NH2. By using reversed-phase HPLC and a chiral mobile phase, it was shown that the 3-phenyllactyl group had the L configuration. Immunocytochemical staining with antiserum against Arg-Asn-NH2 showed that L-3-phenyllactyl-Leu-Arg-Asn-NH2 (Antho-RNamide) was localized in neurons of sea anemones. The L-3-phenyllactyl group has not been found earlier in neuropeptides of vertebrates or higher invertebrates. We propose that this residue renders Antho-RNamide resistant to nonspecific aminopeptidases, thereby increasing the stability of the peptide after neuronal release.
authors.affiliation: Center for Molecular Neurobiology, University of Hamburg, Federal Republic of Germany.
authors.forename: C J
authors.initials: CJ
authors.lastname: Grimmelikhuijzen
authors.forename: K L
authors.initials: KL
authors.lastname: Rinehart
authors.forename: E
authors.initials: E
authors.lastname: Jacob
authors.forename: D
authors.initials: D
authors.lastname: Graff
authors.forename: R K
authors.initials: RK
authors.lastname: Reinscheid
authors.forename: H P
authors.initials: HP
authors.lastname: Nothacker
authors.forename: A L
authors.initials: AL
authors.lastname: Staley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000918:Antibody Specificity; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003063:Cnidaria; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000302:isolation & purification*; D009842:Oligopeptides / Q000138:chemical synthesis; D011863:Radioimmunoassay; D012615:Sea Anemones; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D009479:Neuropeptides; D009842:Oligopeptides; C064978:3-phenyllactyl-leucyl-arginyl-asparaginamide