アミノ酸拮抗物質の研究 第10報

精製Splitting Enzymeによるカナバノコハク酸の生成および分解条件の検討

抄録

Arginosuccinase (splitting enzyme) was purified from the acetone-dried powder of hog kidney, and the decomposition and formation of canavanosuccinic acid was examined with this enzyme. Decomposition of canavanosuccinic acid by purified arginosuccinase is far more inferior than that of arginosuccinic acid. Using 6 units of the enzyme at 37° for 60 minutes, 5 micromoles of arginosuccinic acid was decomposed to 76% while the same amount of canavanosuccinic acid was decomposed to only 6%. In order to decompose the latter to the same extent as the former, it required 40-50 times the amount of enzyme. The reaction was not promoted by extension of the reaction time or the presence of arginase. Formation of canavanosuccinic acid from canavanine and fumaric acid is 54% when using 125 micromoles of the substrate with reaction time of 120minutes, which was relatively close to the formation rate of 75% of arginosuccinic acid. This showed that the formation of canavanosuccinic acid is more easily promoted than its decomposition. Effect of canavanin and canavanosuccinic acid in the decomposition of arginosuccinic acid was examined but they did not seem to have any obstructive effect.