Talesa V, Principato G B, Rosi G, Giovannini E
Boll Soc Ital Biol Sper. 1985 Jan 30;61(1):47-53.
The authors carried out extraction and purification of an alkaline phosphatase (AP) from Hirudo medicinalis and studied certain characteristics of the enzyme. After homogenizing specimens of H. medicinalis and centrifuging the homogenate at 70,000 g, the enzyme, likely membrane-bound, was obtained in a soluble form by treating the sediment with n-butanol. It was then purified by acetone fractionation and Sephadex G-200 chromatography. A fairly good purification degree was achieved; the enzyme appears to be in a single form and displays a molecular weight of about 268,000. The optimum pH (9.5) is lower than the ones generally observed as regards APs from both Invertebrata and Mammalia. The studied AP displays a strong substrate inhibition, similar to that concerning Metazoa at a higher evolutionary level (Mollusca, Echinodermata). On the contrary, the enzyme-substrate affinity, as shown by Km value (2.447 mM), is lower than as regards APs from more advanced organisms (Echinodermata, Mammalia).
作者从医蛭中提取并纯化了一种碱性磷酸酶（AP），并研究了该酶的某些特性。将医蛭标本匀浆，然后在70,000 g下离心匀浆，通过用正丁醇处理沉淀物，以可溶形式获得了可能与膜结合的该酶。然后通过丙酮分级分离和Sephadex G - 200色谱法对其进行纯化。获得了相当高的纯化程度；该酶似乎为单一形式，分子量约为268,000。最佳pH值（9.5）低于通常在无脊椎动物和哺乳动物的碱性磷酸酶中观察到的pH值。所研究的碱性磷酸酶表现出强烈的底物抑制作用，类似于在进化水平较高的后生动物（软体动物、棘皮动物）中观察到的情况。相反，由Km值（2.447 mM）所示的酶 - 底物亲和力低于来自更高级生物（棘皮动物、哺乳动物）的碱性磷酸酶。
