title: Preparation and conformational study of clupeine fragments.
abstract: Fragments of clupeines, YI, YII, and Z of divergent chain length and different amino acid composition were prepared by digestion with thermolysin and a mixture of carboxypeptidases A and B, and their conformational preferences examined as a function of pH, added salts, presence of a helix-supporting solvent, and temperature. All these highly basic oligopeptides adopt an essentially unordered conformation in aqueous solution. 2-Chloroethanol supports in various amounts the onset of the right-handed alpha-helical form in the carboxy-peptidase fragments.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D043424:Carboxypeptidase B; D002268:Carboxypeptidases; D043422:Carboxypeptidases A; D002942:Circular Dichroism; D003026:Clupeine / Q000302:isolation & purification; D010446:Peptide Fragments; D011479:Protamines; D011487:Protein Conformation; D013820:Thermolysin
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D011479:Protamines; D003026:Clupeine; D002268:Carboxypeptidases; D043422:Carboxypeptidases A; D043424:Carboxypeptidase B; D013820:Thermolysin