title: Amino acid sequences of alpha-helical segments from S-carboxymethylkerateine-A. Complete sequence of a type-II segment.
abstract: 1. The helical fragments obtained by partial chymotryptic digestion of S-carboxymethylkeratine-A, the low-sulphur fraction from wool, were fractionated into type-I and type-II helical segments in aqueous urea under conditions limiting carbamoylation. 2. The amino acid sequence of a 109-residue type-II segment was completed by using the sequenator. 3. When the data were incorporated into a helical model of 3.6 residues per turn the hydrophobic residues generated a band aligned at a slight angle to the helical axis. This result is in accord with the postulated coiled-coil structure of the crystalline regions of alpha-keratin.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D002918:Chymotrypsin; D007633:Keratins; D010446:Peptide Fragments / Q000032:analysis; D014935:Wool
chemical_list: D010446:Peptide Fragments; D007633:Keratins; D002918:Chymotrypsin