title: beta-endorphin: synthesis of analogs with extension at the carboxyl terminus with high radioreceptor binding activity.
abstract: Four analogs of human beta-endorphin (beta h-EP) have been synthesized: [Gly31]-Beta h-EP-Gly-NH2, [CH3(CH2)4NH231]-beta h-EP, [Gly31]-beta h-EP-Gly-Gly-NH2, and [Gln8, Gly31]-betah-EP-Gly-Gly-NH2. All are more active than beta h-EP in an opiate receptor binding assay. Stepwise extension at the COOH-terminus shows a progressive increase in binding activity. The last analog, which combines extension at the COOH-terminus with elimination of the remaining anionic charge in beta h-EP, is nine times more active than the parent molecule.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D004723:Endorphins / Q000032:analysis / Q000138:chemical synthesis*; D006801:Humans; D011869:Radioligand Assay; D011957:Receptors, Opioid / Q000032:analysis; D001615:beta-Endorphin
chemical_list: D000596:Amino Acids; D004723:Endorphins; D011957:Receptors, Opioid; D001615:beta-Endorphin