Solubilization of Feather Keratin by a Copper-amine Complex

Chicken feather keratin was solubilized by cupri-ethylenediamine treatment and the solubilized products were separated into acidic and basic fractions by ion exchangers. In the solubilized products which had a molecular weight between 10,000 and 60,000, all the original cystine residues disappeared and cysteic acid residues were recovered instead of them but partly. The cupri-ethylenediamine reagent which catalyzed air-oxidation of cystine residues in keratin was removable mostly from the products by dialysis against water. The common copper-amine complexes were ineffective to solubilize feather keratin except for Schweitzer’s reagent. One strongly basic, unusual amino acid was detected in the basic solubilized fraction. This amino acid was eluted after arginine by usual column chromatography.