Relation between the tyrosine content of various wools and their content of a class of proteins rich in tyrosine and glycine

Abstract

Wool samples can vary in their content of tyrosine by as much as 60%. It has been shown that this is due to variation in their content of a heterogeneous group of proteins which are very rich in tyrosine and glycine (about 1 residue in 5 and 1 residue in 3 respectively). Certain Lincoln wools and some felting lustre mutant Merino wools appear to contain very little of these proteins whereas fine Merino wools may contain as much as 12% by weight of them. As this is too much protein to be accommodated in the cuticular membranes, the currently held site of origin of hightyrosine proteins, it is concluded that at least some of these proteins must be accommodated in an unknown region of the cortex. The variable tyrosine content of wools may be related to observed differences in their rate of photochemical degradation and mechanicochemical properties. © 1971 CSIRO.