Simon F R, Sutherland E
Enzyme. 1977;22(2):80-90. doi: 10.1159/000458774.
Although it is generally believed that hepatic alkaline phosphatase is localized to liver plasma membranes, 63% is present in the cytosol fraction after ultracentrifugation of rat liver homogenates. Divalent cation requirements, heat inactivation, pH optima, Km and chemical inhibition characteristics of partially purified alkaline phosphatase enzymes prepared from membrane and cytosol fractions suggested different structural forms. Furthermore, bile duct obstruction and ethinyl estradiol administration preferentially increased membrane-bound alkaline phosphatase activity, while cytosol activity was unaltered. In contrast, phenobarbital treatment decreased membrane-bound alkaline phosphatase and increased cytosol activity. These studies support the presence of two forms of hepatic alkaline phosphatase in rat liver which are regulated by different control mechanisms.
尽管人们普遍认为肝脏碱性磷酸酶定位于肝细胞膜，但大鼠肝脏匀浆超速离心后，63%的该酶存在于胞质溶胶组分中。从膜组分和胞质溶胶组分制备的部分纯化碱性磷酸酶的二价阳离子需求、热失活、最适pH值、米氏常数（Km）和化学抑制特性表明存在不同的结构形式。此外，胆管阻塞和给予乙炔雌二醇优先增加膜结合碱性磷酸酶活性，而胞质溶胶活性未改变。相反，苯巴比妥治疗降低膜结合碱性磷酸酶活性并增加胞质溶胶活性。这些研究支持大鼠肝脏中存在两种形式的肝脏碱性磷酸酶，它们受不同的调控机制调节。
