岩豆(Millettia dielsiana Harms ex Diels)凝集素的分离纯化和性质研究

Purification and Characterization of Millettia dielsiana Harms ex Diels Lectin

用猪甲状腺球蛋白-Sepharose 4B作亲和吸附剂,再经Sephadex G-100凝胶过滤,可以从岩豆种子中纯化出岩豆凝集素(MDL)。该凝集素可以凝集人类A、B、O型血细胞和兔红细胞,纯化的MDL凝集兔红细胞的能力可被D-松三糖、邻硝基-苯酚-D-半乳糖和N-乙酰半乳糖胺抑制,甘露糖也有弱的抑制作用。纯化的MDL在PAGE和SDS-PAGE上均显现单一蛋白质染色带,经Schiff’s试剂染色证明为糖蛋白;以酚-硫酸法测得其中性糖含量为6.0％;SDS-PAGE测得亚基分子量为32 000;Sephadex G-100分子筛柱测得其分子量为63 800;等电聚焦电泳显示其等电点为5.1;氨基酸组成分析表明其中Asp、Glu、Phe含量较高,但不含有Pro、Tyr。MDL也是一个强促有丝分裂原,对人外周血淋巴细胞转化率可达81.2％,细胞分裂比率达14.8％。

A method is presented for the isolation of a lectin from Millettia dielsi-ana Harms ex Diels seeds by an affinity chromatography on the porcine thyroglobu-lin-Sepharose 4B,followed by gel filtration on Sephadex G-100-This lectin is a gly-coprotein,the molecular weight is 63 800;It consists of two identical subunits.Its isoelectric point is 5.1.The lectin is nonspecific in agglutination for any type of human erythrocytes.The hemagglutinating activity can be inhibited by D-melizitose,O-NO2-phenol-D-galatose,N-actyl-galatosamine and mannose.The lectin is a kind of mitogen,It shows mitogenic activity on human peripheral blood lymphocytes.Amino acid analyses of the purified lectin shows a large amount of aspartic acid and phenylalanine,but no proline and tyrosine can be found in the lectin.