J. S. FRUTON 



molecule. The demonstration of the extremely precise side-chain 

 specificity of the proteolytic enzymes suggests that the synthesis of a 

 protein from amino acids or small peptides could be accomplished only 

 by the cooperative successive action of many enzymes of different 

 specificity. In offering this suggestion, it must be emphasized again, 

 however, that the view that the proteolytic enzymes mediate the bio- 

 synthesis of proteins is not supported as yet by unequivocal experi- 

 mental evidence. There can be no doubt that the efforts of numerous 

 biochemists will be directed in the future to the elucidation of this 

 fundamental problem. 



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