Detection of a novel sequence change in the major form of alpha-MSH isolated from the intermediate pituitary of the reptile, Anolis carolinensis.
Intermediate pituitaries of the reptile, Anolis carolinensis, were separately pulse labeled with [3H]Trp and [3H]Tyr. The major form of alpha-MSH was purified by immunoprecipitation and isolated by reverse phase HPLC. Tryptic peptide analysis indicated that the [3H]Trp-labeled C-terminal fragment of Anolis alpha-MSH had the same retention time as mammalian ACTH(9-13) amide; however, the [3H]Tyr-labeled N-terminal fragment did not coelute with either mammalian ACTH(1-8) or N-acetyl-ACTH(1-8). Purification of alpha-MSH from 76 Anolis intermediate pituitaries confirmed that a sequence change had occurred in the N-terminal region of Anolis alpha-MSH. The tissues were acid extracted and purified by Sephadex G-25 chromatography and reverse phase HPLC to yield 4.5 micrograms of purified Anolis alpha-MSH for amino acid composition analysis and automated Edman degradation sequence analysis. The major form of Anolis alpha-MSH is nonacetylated and has the following novel primary sequence: Ser-Tyr-Ala-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro(Val-amide). The presence of Val-amide was verified by immunological analysis, tryptic peptide analysis and amino acid composition analysis.
Dores
R M
RM
University of Denver, Department of Biological Sciences, CO 80208.
Lancha
A
A
Rand-Weaver
M
M
Jankelow
L
L
Adamczyk
D L
DL
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D005075:Biological Evolution; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010902:Pituitary Gland / Q000737:chemistry*; D012104:Reptiles / Q000378:metabolism*; D000521:alpha-MSH / Q000031:analogs & derivatives / Q000737:chemistry*
D000596:Amino Acids; D010446:Peptide Fragments; D000521:alpha-MSH