Analysis of ACTH-related and CLIP-related peptides partially purified from the pituitary of the Australian lungfish, Neoceratodus forsteri.
Acid extracts of individual lungfish pituitaries were fractionated by gel filtration on a Sephadex G-75 column and aliquots of column fractions were screened with a heterologous ACTH(1-39) radioimmunoassay (RIA). Two major, incompletely separated, peaks of ACTH-related immunoreactivity were detected. These peaks of ACTH-related material were resolved by reverse-phase high-performance liquid chromatography and were designated Peak A and Peak B. Peak A had a retention time more hydrophilic than synthetic human CLIP [ACTH(18-39)], whereas Peak B had a retention time similar to, but not identical with, human ACTH(1-39). Further analysis indicated that Peak A had an apparent molecular weight of 2.5K and an isoelectric point of 4.3. Based on these characteristics, Peak A would appear to be lungfish CLIP. Peak B had an apparent molecular weight of 4.5K. Based on chromatographic and immunological properties, Peak B would appear to be lungfish ACTH. The detection of these lungfish peptides by heterologous RIA indicates a high degree of primary sequence homology between lungfish and tetrapod ACTH-related polypeptides.
Dores
R M
RM
University of Denver, Department of Biological Sciences, Colorado 80208.
Adamczyk
D L
DL
Joss
J M
JM
D000324:Adrenocorticotropic Hormone / Q000032:analysis*; D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D053497:Corticotropin-Like Intermediate Lobe Peptide; D005399:Fishes / Q000378:metabolism*; D007526:Isoelectric Point; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis*; D010902:Pituitary Gland / Q000032:analysis*; D011863:Radioimmunoassay; D012689:Sequence Homology, Nucleic Acid
D010446:Peptide Fragments; D053497:Corticotropin-Like Intermediate Lobe Peptide; D000324:Adrenocorticotropic Hormone