title: Isolation and characterization of alpha-endorphin and gamma-endorphin from single human pituitary glands.
abstract: alpha-Endorphin and gamma-endorphin, two closely related peptides of the pro-opiomelanocortin family with characteristic biological activities, were purified to homogeneity from single human pituitary glands and chemically identified. Isolation of the peptides was based on size fractionation by Sephadex G-75 chromatography followed by two HPLC steps using reverse-phase and paired-ion reverse-phase systems and was monitored by radioimmunoassay. During the isolation procedure alpha- and gamma-endorphin-sized material behaved chromatographically and immunologically indistinguishably from synthetic alpha- and gamma-endorphin. The amino acid composition and NH2-terminus of isolated peptides demonstrated their identity as authentic alpha-endorphin and gamma-endorphin. Acetylated forms were absent. In addition, evidence is provided that large forms with alpha- and gamma-endorphin immunoreactivity detected during gel filtration are human lipotropin-(1-74) and -(1-75), respectively. The data substantiate that alpha-endorphin and gamma-endorphin exist as endogenous peptides in the human pituitary gland.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D002850:Chromatography, Gel / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004723:Endorphins / Q000302:isolation & purification*; D006801:Humans; D010902:Pituitary Gland / Q000032:analysis*; D011863:Radioimmunoassay; D018822:alpha-Endorphin; D018823:gamma-Endorphin
chemical_list: D000596:Amino Acids; D004723:Endorphins; D018822:alpha-Endorphin; D018823:gamma-Endorphin