title: Biosynthesis of pro-opiomelanocortin-derived peptides in the mouse neurointermediate lobe.
abstract: This report concerns biosynthetic studies conducted with neurointermediate lobes of the mouse pituitary gland. High performance liquid chromatography was used to resolve newly synthesized peptides after in-vitro incubation of lobes with radioactive amino acids. Among the newly synthesized peptides identified were alpha-MSH, des-N alpha-acetyl-alpha-MSH, two forms of corticotrophin-like intermediate lobe peptide and beta-endorphin. The biosynthesis of a glycosylated gamma 3-MSH-like peptide was also demonstrated. While no newly synthesized beta-MSH could be identified, a peptide designated gamma-lipotrophin was found. Pulse-chase analysis revealed that the major biosynthetic pathway leading to the production of alpha-MSH involved the acetylation of the des-acetyl form of this peptide. Furthermore, it was evident that newly synthesized beta-endorphin was largely converted to modified forms of this peptide; most of the terminal product was probably N-acetylated endorphin.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000096:biosynthesis*; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D053497:Corticotropin-Like Intermediate Lobe Peptide; D004586:Electrophoresis; D004723:Endorphins / Q000096:biosynthesis*; D005260:Female; D009074:Melanocyte-Stimulating Hormones / Q000096:biosynthesis*; D051379:Mice; D008815:Mice, Inbred Strains; D010452:Peptide Biosynthesis; D010446:Peptide Fragments / Q000096:biosynthesis*; D010902:Pituitary Gland / Q000378:metabolism*; D011863:Radioimmunoassay; D011869:Radioligand Assay; D001615:beta-Endorphin
chemical_list: D000596:Amino Acids; D004723:Endorphins; D010446:Peptide Fragments; D053497:Corticotropin-Like Intermediate Lobe Peptide; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones