title: New segment-coupling method for peptide synthesis in aqueous solution: application to synthesis of human [Gly17]-beta-endorphin.
abstract: The thiolcarboxyl peptide [17-thiolglycine]-beta-endorphin-(1-17) (I) was synthesized by the solid-phase method. Reaction of peptide I with citraconic anhydride gave citraconyl-[Lys(Cit9,GlyS17]-beta-endorphin-(1-17) (Ia). Peptide Ia was coupled to another synthetic peptide, [Lys(Cit)19,24,28,29]-beta-endorphin-(18-31), by reaction with silver nitrate--N-hydroxysuccinimide in water. All citraconyl groups were removed in aqueous acetic acid, and [Gly17]-beta-endorphin was isolated in 30-40% yield. The synthetic analog had 10% analgesic potency and 59% opiate--receptor binding activity when compared with human beta-endorphin.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001681:Biological Assay; D004723:Endorphins / Q000138:chemical synthesis*; D006801:Humans; D008722:Methods; D051379:Mice; D009842:Oligopeptides / Q000138:chemical synthesis*; D010146:Pain / Q000503:physiopathology; D013329:Structure-Activity Relationship; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D009842:Oligopeptides; D001615:beta-Endorphin