A lectin with strong hemagglutination activity was isolated from roots of Sophora flavescens Ait. by extraction, fractionation with (NH 4) 2SO 4, ion-exchange chromatography on DEAE-Sepharose and followed by gel filtration on Sephadex G-150 and HPLC assay. The purified lectin showed a single protein band on PAGE and SDS-PAGE . The molecular weight of S. flavescens lectin was 32 kD when SDS-PAGE and Sephadex G-100 was used. The lectin agglutinated rabbit red blood cells at 0.97 μg/mL and showed no specific agglutination with any type of human erythrocytes. The hemagglutination activity could be inhibited by mannose and levulose and slightly by glucose and maltose. The SFL contained 2.89% neutral saccharide. It could inhibit apparently the growth of the mycelium of Gibberlla saubinetii （Mont.） Sacc.,Piricularia oryzae Cav. and Fusarium vasinfectum Atk. at the dosage of 62 μg. It was determined by Edman that the sequence of the N-terminal thirty amino acids was: T/A/VDXLXFTFSDFDPNGEDLLFQGDAHVTSNN.
苦参凝集素的分离纯化及部分性质研究
邓俊林1 曾仲奎2 鄢波3 黄兴奇3
（1. 重庆师范学院生物系，重庆400047；2 . 四川大学生物系，成都610064；
3. 云南省农业科学院生物技术研究所，昆明650223）
摘要：从苦参 (Sophoraflavescens Ait.)根浸出液经硫酸铵分级 ,得苦参凝集素 (SFL)粗品 ,再经DEAE_Sepharose、SephadexG_1 5 0和HPLC层析 ,获得具有强凝集活性的SFL样品 ,用PAGE和SDS_PAGE检测均为单一蛋白染色带。SDS_PAGE显示SFL分子仅有一条肽链 ,SephadexG_1 0 0和SDS_PAGE测得其分子量均为 32kD。当SFL浓度为 0 .97μg/mL时能凝集兔红细胞 ,无血型专一性 ,其凝血活性可被甘露糖和果糖抑制 ,麦芽糖和葡萄糖有弱的抑制作用 ,凝集素分子含有 2 .89%的中性糖 ;当SFL量为 6 2 μg时 ,对棉花枯萎病菌 (Fusariumvasinfectum Atk .)、小麦赤霉病菌(Gibberllasaubinetii (Mont.)Sacc .)和水稻稻瘟病菌 (Piriculariaoryzae Cav)菌丝体的生长发育有明显地抑制作用。用Edman法在蛋白测序仪上测出SFL的N端肽链 30个氨基酸的排列顺序为 :T/A/VDXLXFTFSDFDP NGEDLLFQGDAHVTSNN。
关键词： 苦参凝集素；凝集素的抑菌作用；N端肽链的序列结构
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