THE KERATINIZATION PROCESS 243 



Soluble derivatives of feather and other keratins. Feather contains less 

 cystine (6-8%) than hair (16-18%) or wool (11-13%) and is more readily 

 dissolved (Jones and Mecham, 1943). About 80% dissolves in 10 M urea, 

 with O'lM mercaptoethanol and 0*2 M lithium chloride and Ward et al. 

 (1946) estimated a molecular weight of 10,000. Ward, High and Lundgren 

 (1946) also examined the protein-detergent complex which is dissolved in 

 bisulphite and sodium alkylbenzenesulphonate. They found a number 

 average molecular weight of 40,000 (50% detergent). Woodin reports the 



Table 18. Amino Acid Composition of a Keratin Derivative 



Extracted from Merino 64's Quality Wool. 



(From Simmonds (1958). Reproduced with permission.) 



isolation of more definite units with molecular weights of the order of 

 10,000 and of a considerable asymmetry (1954a and b). See also p. 163. 



Apart from the work of Jones and Mecham (1943) little effort has been 

 made to examine the other hard keratins. 



There is still, in spite of recent efforts, particularly on the part of the 

 Australian group, much that remains to be explained in the results obtained 

 from the various solubilized keratin proteins. In their detailed study in 

 which viscosity, sedimentation and diffusion measurements were made on 

 both oxidized and reduced products, O'Donnell and Woods (1956a and b) 



