Soluble wool proteins III. Optical rotation

Abstract

The optical rotations, [α]_D, of three soluble wool keratin derivatives have been measured in a large number of solvents using the sodium D line. A wide range of values was recorded. The values obtained for [α]_D varied from -100° in typical protein denaturing agents such as 8M urea and 6M guanidine hydrochloride to near zero in some organic solvent mixtures. The results are interpreted in terms of the percentage of the polypeptide in the helical configuration. The relation between the optical rotation and the effectiveness of a solvent in disaggregating these proteins is discussed. The optical rotations of the proteins derived from wool appear to be influenced by the methods used to solubilize the proteins.