ACTION OF THE ENZYMES. 145 



ing upon the protein. In the same way ascaris extract pre- 

 vents the synthesis of protein (formation of "plastein") when 

 it is added in a corresponding amount to a reaction mixture 

 consisting of proteoses and a proteolytic ferment. 



The constant association of a milk-curdling ferment with a 

 proteolytic ferment the association of caseinase with acid-, 

 alkali-, and ampho-proteinase wherever these ferments have 

 been isolated has given rise to the idea to which attention 

 has already been called elsewhere, that these two ferments are 

 united in a giant molecule, but that different portions of this 

 molecule have different activities. It is of interest, therefore, 

 to add in this connection that antiproteinase, which reduces 

 so markedly the proteolytic activity of the giant molecule, 

 does not affect its milk-curdling power. 



