Morphological Composition of the Cuticle from Chemically Treated Wool

Abstract

The cuticle plays a decisive part in wool processing, and changes in its morphological composition after industrial finishing are of particular interest. The known enzymatic method for determining the content of endo- and exocuticle is not applicable to chemically modified keratins. A new method was developed for calculating the com position of the cuticle from industrially finished wool on the basis of the results of amino acid analysis. The cuticle was isolated by mechanical treatment of wool in sodium dodecyl sulfate solution. A linear relationship was found between the content of the characteristic amino acids, aspartic acid and leucine, and the amount of en docuticle in isolated cuticle. The results were confirmed by quantitating the diagnostic compounds asparagine and N'-(γ-glutamyl)lysine by means of enzymatic hydrolysis. Shrinkproofing processes effected a specific destruction of the exocuticle, while chrome dyeing caused a loss of nonkeratinous proteins from the endocuticle.