抄録
Wool keratin fibers were solubilized in water without any degradation of wool keratin proteins by the derivatization of disulfide (SS) bonds of cystine residues to carboxymethyl alanyl disulfide (CMAD) groups. After the reduction of wool with 0.2M thioglycolic acid (TGA) in 8M urea at pH 10 for 48h at 25°C, 0 .2M dithiodiglycolic acid (DTDG) was added to the solution containing swollen wool fibers and gently stirred for 24h, and then adjusted to pH7.0 with acetic acid, and finally 0.2M sodium bromate was added slowly to the neutral solution, and then the solution was filtered to remove residues after standing for 24h. The filterate containing soluble CMAD wool keratin proteins was fractionated using Sephadex G25, and the fractions were freeze-dried before weighing. The yield obtained was 95.2% on the basis of dry wool fiber. The yield was found to be functions not only of the concentrations of TGA and DTDG, but also the time of reduction and oxidation and pH as well. SDS-gel electrophoresis patterns of CMAD wool keratin proteins prepared below pH 10 were very similar to the wool protein derivatives. FT-IR showed that the soluble wool keratin proteins contain considerable amount of carboxyl groups associated with the CMAD side chain.
