摘要
大瓶螺蛋白腺经磷酸盐缓冲液抽提、硫酸铵分级沉淀、SephadexG-100和Sepharose4B凝胶过滤,可获得在不连续PAGE(pH4.3和pH8.9)上显示单一蛋白质染色带的大瓶螺凝集素(AGL).该凝集素对人血红细胞无血型专一性,但对A型血红细胞的凝集作用最强.AGL的血凝活力可被乳糖或半乳糖所抑制.AGL分子中的中性糖含量为0.24mg/mg蛋白质.用SDS-PAGE法测得其亚基分子量为15000,且只有一种亚基.AGL中Cys和Phe的含量较高,并较耐热.
Ampullaria gigas Spix lectin has been purified hy extraction with PBS,ammonium sulfate fractionation and chromatography on Sephadex G-100 and Sepharose 4B column. The lectin showed one single band both on PAGE (pH4.3 and PH8. 9) and on SDS-PAGE. The result showed that the lectin has only one kind of subunit. The molecular weight of the subunit was 15 000 when SDS-PAGE method was used for molecular weight determination. AGL is a glycoprotein containing 0. 24 mg per mg protein. Amino acid composition analysis showed that there was a large percentage of cystein and phenylamine.AGL can agglutinate four types of human erythrocytes,but it gave the strongest hemagglutination against type A human red blood cells. The hemagglutinating activity can be inhibited by lactose or D-galatose. Stability experiments proved that AGL can endure high temperature treatment.
关键词
软体动物
大瓶螺
凝集素
提纯
Lectin, Ampullaria gigas Spix lectin, Purification, Properties