title: Isolation and structural characterization of peptides related to alpha- and gamma-melanocyte-stimulating hormone (MSH) from the frog brain.
abstract: Peptides that are derived from the processing of proopiomelanocortin were isolated in pure form from the brain of the frog Rana ridibunda. The primary structure of the most abundant of those peptides was established as: Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val. This amino acid sequence is identical to that of mammalian and frog pituitary alpha-melanocyte-stimulating hormone (MSH) and the peptide co-eluted with synthetic desacetyl alpha-MSH, indicating that it is COOH-terminally alpha-amidated. A second component, which exhibited a shorter retention time, co-eluted with the glycine-extended form of desacetyl alpha-MSH [ACTH(1-14)]. The primary structure of the third peptide isolated in pure form from the brain extract was established as: Lys-Tyr-Val-Met-Ser-His-Phe-Arg-Trp-Asn-Lys-Phe-NH2. This sequence corresponds to Lys-gamma 1-MSH as predicted from the nucleotide sequence of frog proopiomelanocortin. The presence of substantial amounts of desacetyl alpha-MSH and Lys-gamma 1-MSH in the frog brain supports the concept that, in amphibia, melanotropins may act as neurotransmitters and/or neuromodulators as well as hormonal peptides.
authors.affiliation: European Institute for Peptide Research, CNRS URA 650, UA INSERM, University of Rouen, Mont-Saint-Aignan, France.
authors.forename: D T
authors.initials: DT
authors.lastname: Bunel
authors.forename: J M
authors.initials: JM
authors.lastname: Conlon
authors.forename: N
authors.initials: N
authors.lastname: Chartrel
authors.forename: M C
authors.initials: MC
authors.lastname: Tonon
authors.forename: H
authors.initials: H
authors.lastname: Vaudry
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001923:Brain Chemistry / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D009074:Melanocyte-Stimulating Hormones / Q000032:analysis / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis / Q000302:isolation & purification*; D011333:Pro-Opiomelanocortin / Q000032:analysis / Q000302:isolation & purification; D011895:Rana ridibunda; D000521:alpha-MSH / Q000032:analysis / Q000302:isolation & purification*
chemical_list: D000596:Amino Acids; D010455:Peptides; D000521:alpha-MSH; D011333:Pro-Opiomelanocortin; D009074:Melanocyte-Stimulating Hormones