竖琴海豹肠黏膜碱性磷酸酶四聚体同工酶K的化学修饰与组成

Chemical modification and composition of tetrameric isozyme K of alkaline phosphatase from harp seal intestinal mucosa.

Makarova I E, Ermolin G A

Laboratory of Biologically Active Substances of Hydrobionts, Ministry of Health, Moscow, USSR.

Comp Biochem Physiol B. 1989;92(1):119-22. doi: 10.1016/0305-0491(89)90322-2.

Abstract

The carbohydrate content of isozyme K of alkaline phosphatase (EC 3.1.3.1) from harp seal intestinal mucosa was examined. The presence of N-acetylglucosamine, N-acetylgalactosamine and considerable amounts of mannose residues was shown. 2. The amino acid content of seal alkaline phosphatase was determined. A high extent of homology (85%) between bovine and seal alkaline phosphatases was demonstrated. 3. By chemical modification lysine, dicarboxylic acids, arginine and tyrosine residues of tetrameric seal alkaline phosphatase are located near or at the active site. By contrast, the modification of either thiol or imidazole groups resulted in no alterations of the enzyme activity. 4. It has been demonstrated that inorganic phosphate is an inhibitor of alkaline phosphatase and entirely prevents the enzyme inactivation with succinic anhydride.

摘要

对竖琴海豹肠黏膜碱性磷酸酶（EC 3.1.3.1）同工酶K的碳水化合物含量进行了检测。结果表明存在N-乙酰葡糖胺、N-乙酰半乳糖胺以及大量的甘露糖残基。2. 测定了海豹碱性磷酸酶的氨基酸含量。结果显示牛碱性磷酸酶与海豹碱性磷酸酶之间具有高度同源性（85%）。3. 通过化学修饰发现，四聚体海豹碱性磷酸酶的赖氨酸、二羧酸、精氨酸和酪氨酸残基位于活性位点附近或活性位点处。相比之下，巯基或咪唑基团的修饰不会导致酶活性的改变。4. 已证明无机磷酸盐是碱性磷酸酶的一种抑制剂，并且能完全防止该酶被琥珀酸酐灭活。