Gel Filtration Studies of the Binding of Cu (II) by Component Proteins from Wool Keratin

Abstract

The binding of Cu(II) by various keratin derivatives solubilized from wool has been investigated by using gel filtration method in order to understand the nature of Cu(II) complexes with denatured keratin proteins at the molecular level. For this purpose, three types of S-substituted derivatives were prepared from reduced wool, and a sulfonic acid derivative from oxidized wool. The high-sulfur component of each derivative was isolated and used for the experiments. The S-substituted groups introduced were carboxymethyl, α, β-dicarboxyethyl and aminoethyl. Gel filtration experiments were carried out on a Sephadex G-25 gel column using acetate buffer in a pH range of 4.5-6.5 as effluent. The binding data obtained were analysed in terms of two classes of independent binding sites with high and low binding constants, according to a similar procedure to that described by Klotz et al. It was found that the binding parameters for the Cu(II)-keratin complexes depend prominently on the kind of functional groups introduced. These results are discussed in relation to the primary structure of the high-sulfur keratin component. © 1981, The Society of Polymer Science, Japan. All rights reserved.