Melanin concentrating hormone. V. Isolation and characterization of alpha-melanocyte-stimulating hormone from frog pituitary glands.
The structure of alpha-melanocyte-stimulating hormone (alpha-MSH) has been determined in the pars intermedia of the frog Rana ridibunda. Pulse-chase labeling of frog neurointermediate lobes with selective amino acids revealed that the composition of frog alpha-MSH is similar to that of alpha-MSH from all mammalian species yet studied. Tryptic mapping of nexly synthetized alpha-MSH generated two fragments with the following amino acid composition: (T1) Trp, Pro, Lys, Gly, Val and (T2) Tyr, Arg, Phe, His, Ser, Glu. Concurrently, alpha-MSH was purified from 100 neurointermediate lobes to apparent homogeneity by reverse-phase HPLC. The sequence of the peptide determined by automated Edman degradation was Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val. The structure of frog alpha-MSH is thus identical to mammalian des-N alpha-acetyl alpha-MSH and differs from the sequence of toad (Xenopus laevis) alpha-MSH only by the first residue (Ser instead of Ala). These results confirm that the sequence of alpha-MSH has been highly preserved during evolution.
Tonon
M C
MC
URA CNRS 650, Unité Affiliée à l'INSERM, Université de Rouen, Mont-Saint-Aignan, France.
Desrues
L
L
Lazure
C
C
Jenks
B G
BG
Chrétien
M
M
Vaudry
H
H
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005075:Biological Evolution; D002851:Chromatography, High Pressure Liquid; D008297:Male; D008969:Molecular Sequence Data; D010904:Pituitary Gland, Posterior / Q000032:analysis*; D011895:Rana ridibunda / Q000378:metabolism*; D011898:Ranidae / Q000378:metabolism*; D012689:Sequence Homology, Nucleic Acid; D014982:Xenopus laevis; D000521:alpha-MSH / Q000302:isolation & purification*
D000596:Amino Acids; D000521:alpha-MSH