title: The amino acid sequence of protein SCMK-B2C from the high-sulphur fraction of wool keratin.
abstract: 1. The amino acid sequence of a protein from the reduced and carboxymethylated high-sulphur fraction of wool has been determined. 2. The sequence of this S-carboxymethylkerateine (SCMK-B2C) of 151 amino acid residues displays much internal homology and an unusual residue distribution. Thus a ten-residue sequence occurs four times near the N-terminus and five times near the C-terminus with few changes. These regions contain much of the molecule's half-cystine, whereas between them there is a region of 19 residues that are mainly small and devoid of cystine and proline. 3. Certain models of the wool fibre based on its mechanical and physical properties propose a matrix of small compact globular units linked together to form beaded chains. The unusual distribution of the component residues of protein SCMK-B2C suggests structures in the wool-fibre matrix compatible with certain features of the proposed models.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002848:Chromatography, DEAE-Cellulose; D004590:Electrophoresis, Paper; D007633:Keratins / Q000032:analysis*; D008954:Models, Biological; D010455:Peptides / Q000032:analysis; D013455:Sulfur; D014935:Wool / Q000032:analysis*
chemical_list: D000596:Amino Acids; D010455:Peptides; C002552:S-carboxymethylkerateine; D007633:Keratins; D013455:Sulfur