title: Evidence for tertiary structure in aqueous solutions of human beta-endorphin as shown by difference absorption spectroscopy.
abstract: The presence of a distinct tertiary structure in aqueous solutions of human beta-endorphin has been demonstrated by difference absorption spectroscopy of thermolysin digests of the hormone and synthetic analogues. The results demonstrate that the alpha-amino group of Tyr1, Lys28, and some residue(s) between Thr6 and Ser10 are involved in forming and stabilizing the folded form of the molecule. Although a peptide corresponding to the first nine residues of human beta-endorphin shows definite evidence of tertiary structure, the pentapeptide methionine-enkephalin does not.
mesh_terms: D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins; D006801:Humans; D046911:Macromolecular Substances; D010446:Peptide Fragments / Q000032:analysis; D011487:Protein Conformation; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013820:Thermolysin; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D046911:Macromolecular Substances; D010446:Peptide Fragments; D012996:Solutions; D001615:beta-Endorphin; D013820:Thermolysin