title: Purification and characterization of high-molecular-weight forms of adrenocorticotropic hormone of ovine pituitary glands.
abstract: A highly purified preparation of high-molecular-weight adrenocorticotropic hormone (ACTH) was prepared from ovine pituitary glands by dilute acetic acid extraction, oxycellulose fractionation. Sephadex gel filtration, and affinity chromatography on immobilized alphap(1-39)ACTH antibodies. Two ACTH peptides of molecular weights of 24 000 and 34 000 were detected by sodium dodecyl sulfate-acrylamide gel electrophoresis in this preparation. It appeared that the immobilized antibodies adsorbed two forms equally well and could not distinguish between them under the conditions used. These two ACTH peptides were found to be present in crude extracts of ovine pituitary glands, indicating that they were not artifacts produced by the purification procedure. The high-molecular-weight forms of ACTH were found to be susceptible to degradation by tissue enzymes. They could be easily destroyed during the extraction, if precautions were not taken. Moreover, they were poorly adsorbed by oxycellulose which had been used for the adsorption of ACTH activity from crude preparations by most investigators. These properties probably accounted for the fact that high-molecular-weight forms of ACTH remained undetected until very recently.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000302:isolation & purification*; D000327:Adsorption; D000818:Animals; D002482:Cellulose / Q000031:analogs & derivatives; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis; D010902:Pituitary Gland / Q000032:analysis*; D011134:Polysaccharides / Q000032:analysis; D012756:Sheep
chemical_list: D010455:Peptides; D011134:Polysaccharides; D000324:Adrenocorticotropic Hormone; D002482:Cellulose