孔石莼(Ulva pertusa)凝集素的分离纯化及性质的研究

为抑制肿瘤细胞增殖和防治有关病害提供基础理论依据 ,将孔石莼 (Ulva pertusa)经磷酸盐缓冲液抽提 ,2 0 %～ 75%硫酸铵分级沉淀 ,牛甲状腺球蛋白 - Sepharose4B亲和层析 ,可以从绿藻孔石莼中纯化出孔石莼凝集素 (UPL) ,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 p I为 8.40 .纯化后的 UPL的最大紫外吸收峰在 2 85nm,用 Sephadex G- 2 0 0分子筛层析测得其分子量为 1 1 0 4 7.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 (A、B、AB、O)兔、鲤、鲫的红细胞的凝集作用中 ,兔的凝集作用最强 .该凝集素凝集兔红细胞的作用不被 D-半乳糖、D-果糖、葡萄糖、蔗糖、甘露聚糖、γ球蛋白、卵清蛋白所抑制 ,仅被牛甲状腺球蛋白抑制 ,最小抑制浓度为 6.2 0 g/L.该凝集素在 p H4.0～ 1 0 .1 4范围内均有活性 ,但在p H6.50～ 9.51范围内活性较高 ,该凝集活性在 85℃加热 1 h,活力仍未改变 ,说明具有很强的耐热性 .

Isolation,Purification and Properties of Lectin from Ulva pertusa

Isolation,purification and properties of lectin from Ulva pertusa were conducted to elucidate the function in inhibition for tumor cell roproduction and the disease prevention and treatments.The green alga Ulva pertusa lection(UPL)had been purified by extraction with PBS,followed by 20%～75% ammonium sulfate fractionation and an affinity chromatography on the Bovine thyroglobulin Sepharose 4B colum.There appeared one single band of lectin on both PAGE and Isoelectrofocusing electrophoretic.Its isoelectric point was 8.40,with peak absorption at 285 nm.its molecular weight was 11 047 on Sephadex G 200.The UPL was nonspecific in agglutination for any type of human erythrocytes,and the hemagglutinating activity was equal.The agglutination for rabbits was the highest,among erythrocytes of humans(A,B,AB,O),rabbits,common carp and crucian carp.The hemagglutinating activity for rabbit could not be inhibited by D fructose, D galactose,glucose,sucrose,mannan,gamma globulin(human)and egg albumin,but inhibited by bovine thyroglobulin and the minimum inhibitory concentration was 6 20 g/L.This lectin had the maximum hemagglutinating activity at pH 6 50-9 51,with activity at pH4 0-10 14.The hemagglutinating activity was not affected by heating for 60 min at 85℃.So it had high heat resistance.