Studies on the properties of glucose-6-phosphatase from carp liver microsomes (Cyprinus carpio L.)

The effects of temperature and pH on the phosphohydrolase activity of carp hepatic glucose-6-phosphatase (EC 3.1.3.9) have been investigated. The enzyme activity was maximum at about 308 K and in the pH range 5-6.5. The apparent Michaelis constant (KM) and Vmax of the reaction with glucose-6-phosphate were found to be 14.8 mM and 2.27 nmol/min/mg protein. The enzyme activity was partly inhibited by EDTA, while in the presence of sufficient PCMB virtually total inhibition was observed.