Inorganic Phosphate Has the Inhibitory Effect on Phosphotyrosyl Phosphatase Activity of Alkaline Phosphatase in Rabbit Plasma

인산에 의한 토끼 혈장 Alkaline Phosphatase의 Phosphotyrosyl Phosphatase 활성 저해

Inorganic phosphate (Pi) in rabbit plasma was found to block completely phosphotyrosine phosphatase (PTPase) activity without affecting the alkaline phosphatase (ALPase) activity. Our results provided that (1) PTPase activity and inhibitor are separated after G-25 gel-filtration. (2) This inhibitor is heat stable and trypsin-resistant and it can be removed by dialysis using 3 Kd cut-off tubing. (3) The elution pattern of the inhibitor is identical to that of Pi, and by performing a seperate run with inorganic phosphate. (4) The PTPase activity was recovered following an incubation with $CaCl_2$ (10 mM).