Studies on the Alkaline Phosphatase of Pekin Duck: I. Some Properties of Liver Alkaline Phosphatase

Some properties of alkaline phosphatase, partially purified from the liver of the local Pekin duck, Anas platyrhynchos, were investigated with the following results. 1. Gel-filtration of the duck liver extract indicated the presence of two molecular-weight species of alkaline phosphatase. 2. Electrophoresis of both enzyme preparations suggests the presence of two molecular forms of alkaline phosphatase with different physicochemical characteristics. 3. The liver alkaline phosphatase has an optimum pH of 9.0, and is further activated by $Mg^2+$ but not by $Ca^2+$. 4. The enzyme was relatively heat-labile, and was competitively inhibited by phosphate ions, but uncompetitively inhibited by L-phenylalanine. 5. These results are discussed in comparison with the properties of human and other animal alkaline phosphatases.

中國産 집오리, Anas platyrhynchos의 肝 alkaline phosphatase의 特性에 대해 觀察하여, 다음과 같은 結果를 얻었다. 1. 이 酵素는 分子의 크기가 다른 2가지 酵素種을 가짐을 보였다. 各 酵素分子는 各各 電氣泳動 速度가 다른 2가지 分子로 이루어 짐을 알았다. 2. 이 효소의 最適 pH는 9.0임이 판명되었고, 다른 포유류 酵素에 比해 熱에 대한 安定度가 낮았다. 3. $Mg^2+$은 이 酵素의 活性을 약 2배 증가 시켰으나, $Ca^2+$은 活性에 거의 影響을 주지 않았다. 4. Phosphate 이온은 이 효소에 대해 competitive, L-phenylalanine은 uncompetitive 阻害劑로 作用함을 알았다.