酶标白桂木凝集素糖蛋白结合特性的分析

采用辣根过氧化物酶 ( HRP)标记白桂木凝集素 ( AHL) ,应用酶联夹心法及糖竞争抑制实验 ,研究 AHL的糖蛋白结合特性 .研究表明 ,AHL能与两种不同类型的糖蛋白结合 ,一类以胃蛋白酶为代表 ,AHL能以高亲和力与胃蛋白酶结合 .其次能与β-乳球蛋白、牛血清清蛋白结合 ,但结合力依次递减 .AHL也能与透明质酸以较高亲和力相结合 .AHL与胃蛋白酶、β-乳球蛋白、牛血清清蛋白、透明质酸的结合受 Me- Gal的强烈竞争抑制 ,亦受 Me- Man\D- Gal\Raf的抑制 .另一类为Con A,AHL与 Con A的结合受 Me- Man的强烈竞争抑制 ,并受 Me- Glc\D- Man\D- Fru\D- Glc的较强抑制 .各种糖的封闭性抑制实验结果与竞争性抑制实验相似 .提示 AHL上存在 O-糖苷键结合位点 .

Characterization of Artocarpus hypargyreus Lectin Interacting With Glycoproteins

AHL( Artocarpus hypargyreus Lectin)had been purified by fractionation of (NH 4) 2SO 4 precipitation followed by affinity chromatography on Gal Sepharose 6B. Carbohydrate assays indicated that AHL was a kind of glycoprotein. β elimination revealed that AHL contained O glycoside linkage. AHL HRP was prepared and the characteristics of AHL interacting with glycoproteins were assayed by Sandwich enzyme linked method. The results indicated that AHL could bind two kinds of glycoproteins, in which one was pepsin, and the other was Con A. The affinity of AHL with pepsin was very high. AHL could also bind hyaluronic acid, β lactoglobulin, and bovine serum albumin by successively decreasing affinity. The combination of AHL with pepsin, hyaluronic acid, β lactoglobulin, or bovine serum albumin was strongly inhibited by Me Gal, and also inhibited by Me Man, D Gal, and Raf. The combination of AHL with Con A was strongly inhibited by Me Man, secondly by Me Glc, D Man, D Fru, and D Glc. The results suggest that AHL contains a site to bind O glycoside linkage.