Regulation of alkaline phosphatase and the relation with calcification in hard tissues.

钙骨碱性磷酸酶（AlP）的活动按温度和pH值调节，温度高于32-35 ° C，基质饱和度曲线为pH为10.5的Michaelis型或pH为7.5的基质抑制型。在32-35 ° C以下，在另一边，在pH值10.5和7.5下观察到的有利和消极的合作，尊重地。对磷酸盐活性的重新研究（P-Tyr， P-Ser和P-Thr）与<^（31）P>核磁共振光谱学指标：（1）在一个基底系统中，脱磷作用的初始速度在三种磷酸盐中是明显的，但稳定状态下的P-Tyr的速度高于P-Ser和P-Thr的速度; （2）在两个基础系统中，初始状态和后稳定状态下的速度都高于P-Ser和P-Thr的速度;和（3）醇基羟基组在Ser或Thr中被解磷基化产品重磷基化，并被转磷基化酶的作用所取代。这些事实表明，酶在体内的生理功能可能是磷酸盐浓度在硬组织中的调节，而转化反应则是如此。

The activity of calf bone alkaline phosphatase (AlP) was regulated with temperature and pH. At the temperature above 32-35 ゜C, the substrate saturation curve was a Michaelis type at pH 10.5 or a substrate inhibition type at pH 7.5. Below 32-35 ゜C, on the other hand, the possitive and negative cooperativities were observed at pH 10.5 and 7.5, respectively.The reexamination of AlP activity for phosphoamino acids (P-Tyr, P-Ser and P-Thr) with <^(31)P> NMR spectroscopy indicated: (1) in the one-substrate system, the initial velocity of dephosphorylation was identical among three phosphoamino acids, but the velocity with P-Tyr after the steady state was higher than those with P-Ser and P-Thr; (2) in the two-substrate system, both of the initial and post-steady state velocities with P-Tyr were higher than those with P-Ser and P-Thr; and (3) alcoholic hydroxyl group in Ser or Thr as the dephosphorylation product was rephosphorylated by the transphosphorylase action of AlP. These facts implies that the physiological function of the enzyme in vivo may be the regulation of phosphate concentration in hard tissues with the transphosphorylation action.