掌叶半夏凝集素A的分离纯化及分析

PURIFICATION AND CHARACTERIZATION OF PINELLIA PEDATISECTA LECTIN A

首次从中草药掌叶半夏（ＰｔｎｅｌｌｉａｐｅｄａｔｉｓｅｃｔａＳｃｈｏｔｔ）中通过ＳｅｐｈａｄｅｘＧ－１００分子筛层析、ＤＥ－３２离子交换层析和制备电泳分离纯化出一种对兔红血球有血凝活性的凝集素，称之为掌叶半夏凝集素Ａ（ＰｉｎｅｌｌｉａｐｅｄｔａｉｓｅｃｔａｌｅｃｔｉｎＡ，ＰＰＬ－Ａ）。在ＰＡＧＥ、ＳＤＳ－ＰＡＧＥ和等电聚焦电泳上ＰＰＬ－Ａ均显示出一条蛋白质着色带，经ＳＤＳ－ＰＡＧＥ测定其Ｍｒ为１６．３×１０３，用等电聚焦电泳测得其等电点为５．８，经ＤＮＳ－Ｃｌ分析法分析其氨基末端为丙氨酸。对所含的１８种氨基酸作了定量分析。通过Ｓｃｈｉｆｆ试剂电泳染色法鉴定ＰＰＬ－Ａ为糖蛋白，用酶标凝集素结合法分析了糖链的结构，糖链部分含有甘露糖，岩藻糖和乙酰氨基葡萄糖。

A novel lectin,which was named Pinellia pedatisecta lectin A(PPL-A),was purified from the stem tuber of Pinellia pedatisecta Schott by chromatography on Sephadex G-100 and DE-32 cellulose and preparative electrophoresis. PPL-A showed a single band on disc polyacrylamide gel electrophoresis,SDS-PAGE and isoelectric focusing.The molecular weight of PPL-A was estimated to be 16.3 × 103 by SDS-PAGE. Its isoelectric point is 5.8.The N-terminal amino acid is alanine PPL- A is a glycoprotein containing mannose, fucose, N-acetylglucosamide and 18 amino acids and is rich in aspartic acid and glycine. The structure of the sugar chains in the molecular of PPL-A was analysed by horseradish peroxidase conjugating 4 different lectins,LCA,WGA,ConA,and EPHA. PPL-A exhibits a hemagglutinating activity to rabbit erythrocytes at the concentration of 20mg/L.