大瓶螺凝集素的分离纯化及部分性质研究

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．

Studies on the Purification and Properties of Ampullaria gigas Spix lectin

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.