A basic protein fraction having toxohormone activities, isolated from rat Rhodamine sarcoma, was subjected to enzymatic hydrolysis with trypsin, pepsin, and pronase, resulting in the splitting of 12.3%, 19.1%, and 57.4% of peptide bonds of the basic protein respectively.
The effect of the hydrolysis on the toxohormone activities of the basic protein was determined by bioassay with rats or mice. Liver catalase depression was markedly diminished by hydrolysis with pronase and pepsin but not by trypsin. Plasma iron decrease was affected by none of these enzymes. Liver tryptophan pyrrolase depression was markedly diminished by hydrolysis with any one of these enzymes.
These results suggest that these three different activities of toxohormone are associated with different chemical entities of the basic protein.
