抄録
1. Studies were made to test whether purine nucleotides other than inosinic acid activated thiamine diphosphate in liver-pyruvate oxidase system and adenosine monophosphate and guanosine monophosphate were found to increase markedly the enzyme activity.
2. In parallel experiments, the metabolic fate of inosinic acid was investigated by paper chromatography, and it was found that there were several pathways for the degradation of the nucleotide linked to the enzyme activation. The results seem to suggest that inosine might accelerate the thiamine diphosphate activity of liver-pyruvate oxidase system.
3. Supplement of inosine or hypoxanthine to D-ribose was found to accelerate the thiamine diphosphate action in liver-pyruvate oxidase system, while no activation was detected after addition of hypoxanthine alone. The final reaction mixture was tested by paper chromatography and the reappearance of inosine after adding both hypoxanthine and D-ribose was confirmed.
These findings lead to the conclusion that the metabolism of inosine may accelerate the thiamine diphsophate activity in liver-pyruvate oxidase system.
