Studies on Reduced Wool V. A Comparison of the Two Major Components

Abstract

Starch-gel electrophoresis of wool proteins extracted from reduced and carboxymethylatedwool gives a complex pattern in which there are 2 major protein bands. By a combination chromatography on DEAE-cellulose and gel-filtration in buffers containing 8[image] urea these 2 protein components have been isolated. The amino acid composition and some properties of these 2 fractions are reported. A comparison of the amino acid composition and of peptide maps of tryptic digests of the 2 fractions shows distinct differences between them, and by labelling with 2-[C14]io-doacetate the distribution of the peptides containing S-carboxymethyl-cysteine residues were also shown to be different. The molecular weight of the 2 protein components was estimated to be about 45,000 by comparison of their elution volumes on gel-filtration with the elution volumes of reduced and carboxymethylated proteins of known molecular weight. Gel-filtration was carried out in 8[image] urea, 14[image] formamide, and 5[image] guanidine hydrochloride, and no evidence of further dissociation of these components was obtained.