角叉菜凝集素的分离纯化及其性质

Isolation and purification of lectin from Chondrus ocellatus and the lectin properties

角叉菜（ Ｃｈｏｎｄｒｕｓ ｏｃｅｌｌａｔｕｓ）经磷酸盐缓冲液抽提， ２０％～ ７５％硫酸锭分级沉淀，牛甲状腺球蛋白一Ｓｅｐｈａｒｏｓｅ ４Ｂ亲和层析，可以从红藻角叉菜中纯化出角叉菜凝集素（ＣＯＬ），在 ＰＡＧＥ上显示单一蛋白染色带，在等电聚焦电泳上显示单一蛋白染色带，其ＰＩ为８．３０。纯化后的ＣＯＬ的最大紫外吸收峰在２８５ ｎｍ，用ＳｅＰｈａｄｅｘＧ－２００分子筛层析测得其分子量为 ４ ２５２。该凝集素可以凝集人的Ａ、Ｂ、ＡＢ、Ｏ型红细胞，且凝集活性相同，在对人、兔、鲤、鲫的红细胞的凝集作用中，对兔红细胞的凝集作用最强，且不被己测试的Ｄ－半乳糖、Ｄ－果糖、Ｄ－甘露糖、葡萄糖、蔗糖、甘露聚糖、ｒ－球蛋白、卵清蛋白所抑制，仅被牛甲状腺球蛋白抑制，最小抑制质量浓度为 ３．１０ ｍｇ／ｍｌ。

The lectin from red algae Chondrus ocellatus (COL) was purified by extraction with PBS, followed by 20% - 75% ammonium sulfate fractionation and an affinity chromatography on the Bovine- thyroglobulinSepharose 4B column. One single band appeared on both PAGE and isoelectrofocusing electrophoretogram of the lectin. Its isoelectric Point was 8. 30, with peak abSOrption at 285 nm. Its molecular weight was 4 252 on sephadexG-200. The COL was nonspecific in agglutination for any type of human erythrocytes, and the hemagglutinating activities were all at the same level. The agglutination for rabbit was the highest among erythrocytes of human(A, B, AB, O), rabbit, common carp and crucian carp. The hemagglutinating activity for rabbit could not be inhibited by D-fructose, D-mannose, D-galactose, glucose, sucrose, mannan, gamma- globulin (human ) and egg albumin, but inhibited by bovine-thyroglobulin, and the minimum inhibitory concentration was 3. 10 mg/ ml.