Abstract
The reaction rates of hydrolysis and de-carboxylation of γ-hydroxyarginine catalyzed by arginase and arginine decarboxylase were determined and compared with those of argi-nine. The apparent reaction velocity of hydrolysis of γ-hydroxyarginine was about II per cent of that of arginine, and that of decarboxylation was about 16.5 per cent. The Michaelis constants of arginase and arginine decarboxylase for γ-hydroxyarginine were also calculated and the following data were obtain-ed; 1.6×10-2M in the arginase reaction and 7.6×10-3M in the decarboxylase reaction.
The author wishes to express his cordial thanks to Prof. S. Shibuya for his guidance and encourage-ment. His thanks are also due to the Ministry of Education for financial support of this research.
