磷酰胆碱作为人肠碱性磷酸酶的独特底物。

Phosphorylcholine as a unique substrate for human intestinal alkaline phosphatase.

Irino T, Matsushita M, Sakagishi Y, Komoda T

Department of Clinical Chemistry, Saitama College of Health, Japan.

Int J Biochem. 1994 Feb;26(2):273-7. doi: 10.1016/0020-711x(94)90157-0.

Abstract

The enzymatic nature of human liver, bone, placental and intestinal alkaline phosphatases (ALPs) were investigated with phosphorylcholine (PC), phosphorylethanolamine, pyridoxal-5'-phosphate and p-nitrophenylphosphate at a weakly alkaline pH. 2. The apparent Km value of the intestinal ALP with PC was the highest of all ALPs tested. Intestinal ALP hydrolyzes PC the most and has higher affinity for choline as a transphosphorylating acceptor than the other ALPs. In addition, the intestinal ALP activity with PC was most susceptible to Na2HPO4, in the tested ALPs. 3. The present results suggest that PC is a unique substrate for human intestinal ALP, which may be related to the metabolism of PC or choline as part of phosphatidylcholine.

摘要

在弱碱性pH条件下，使用磷酸胆碱（PC）、磷酸乙醇胺、磷酸吡哆醛-5'-磷酸和对硝基苯磷酸对人肝、骨、胎盘和肠碱性磷酸酶（ALP）的酶学性质进行了研究。2. 在所测试的所有碱性磷酸酶中，肠碱性磷酸酶与PC的表观Km值最高。肠碱性磷酸酶对PC的水解作用最强，作为转磷酸化受体，其对胆碱的亲和力高于其他碱性磷酸酶。此外，在所测试的碱性磷酸酶中，肠碱性磷酸酶与PC的活性对Na2HPO4最为敏感。3. 目前的结果表明，PC是人类肠碱性磷酸酶的独特底物，这可能与PC或胆碱作为磷脂酰胆碱一部分的代谢有关。