Identification and quantitation of major structural proteins from enriched cuticle fractions of wools of different breeds

Abstract

The cuticle plays an important role in determining characteristic traits of wool fibres, but little is known about the identity and abundance of its proteinaceous constituents and whether there are unique differences in cuticle composition of wools from different breeds of sheep. In this study, protein profiles of enriched endocuticle fractions from fine (Merino), strong (Romney) wool and a sheep that sheds its wool (Wiltshire) were determined by LC-MS/MS and LC-MALDI, quantitative differences being determined by iTRAQ-labelling. Although keratin composition of the cuticle was similar between breeds, with the exception of K82, there were clear differences in the number of identified keratin-associated proteins. Overall, both qualitative and quantitative differences in protein composition of the cuticle from different sheep breeds were found, which may contribute to the unique characteristics of these wools.