Study of glucose-06-phosphatase and acid phosphatase activities of the liver in mice

Abstract

The existence is proved of specific glucose-6-phosphatasic activity, with maxi­mum hydrolysis at pH 6.2-6.9, in the homogenates of the liver of the mouse.

Using FF as a substratum, the presence in the.se homogenates of an acid phosphatase, with maximum hydrolysis at pH 5.5-5.8, becomes evident.

The curves of thermic inactivation have proved that the G-6-Phase is a highly thermolabile enzyme, the enzymatic activity being completely destroyed when the homogenate is submitted to a temperature of 50º C for 30 minutes. On the other hand, the acid phosphatase is more tliermoresistant, only a slight decrease being observed in the phosphatasic activity after heating of the homo­ genate to 50º C for 30 minutes.

Acetone in a concentration of 30 % totally destroys the glucose-6-phosphatasic activity of the homogenates of mouse liver. On the other hand, the activity of the acid phosphatase remains unchanged with a concentration of acetone of 30 and 60 %.

The citrate ion at a concentration of 0.02 M in the incubation liquid strongly activates the glucose-6-phosphatase of the homogenate (P < 0.001), while it only seems to activate slightly the acid phosphatase (0.4 < P <Z 0.5). The 0.06 M concentration of citrate ion, however, strongly inhibits both enzymatic activi­ties, and the 0.12 M concentration des­ troys them entirely.