Experiments on the formation of carboxylase and thiamine pyrophosphate in living bakers' yeast

Abstract

The formation of carboxylase by living bakers' yeast was demonstrated upon incubation of the yeast with either thiamine or 2-methyl-4-amino-5-ethoxymethylpyrimidine, in the presence and in the absence of glucose. Carboxylase is also formed upon incubation of the yeast with NH4 sulfate and glucose. In the presence of glucose the effects of thiamine + NH4 sulfate or 2-methyl-4-amino-5-ethoxymethylpyrimidine + NH4 sulfate considerably surpass the effects of any of these substances separately.

The effect of 2-methyl-4-amino-5-ethoxymethylpyrimidine depends upon the primary formation of thiamine pyrophosphate.