쥐의 각 기관별 단백질 탈인산화효소의 활성에 대한 최적 수소이온 농도

To determine optimal pH values for the enzyme activities of phosphoserine/threonine protein phosphatases and phosphotyrosine protein phosphatases, crude tissue extracts obtained from several rat organs were analyzed on enzymic properties, such as the optimal pH value on pNPP hydrolysis, the sensitivity to several enzyme inhibitors/activators, and the protein phosphatase activity toward exogeneous protein substrates. As a result, the activities of phosphoserine/threonine nine protein phosphatases in liver, lung, and prostate were maximal at neutral pH condition. Optimal pH condition for the enzyme activities in spleen and testis was, however, acidic. The enzyme activities in brain and kidney were high at neutral and alkaline pH condition, both. Stomach enzyme exhibited strong activity at acidic condition as well as neutral condition. On the other hand, phosphotyrosine protein phosphatases in brain, lung, liver, spleen, and testis exhibited maximal activities at neutral condition. The activities of phosphotyrosine protein ' phosphatases in kidney and prostate were highest at acidic condition, and the enzyme activity in stomach was high at both acidic and neutral condition. These results provide a valuable information for the future studies on the purification and characterization of phosphoserine/threonine protein phosphatases and phosphotyrosine protein phosphatases in rat organs