芦荟凝集素的理化性质及其对动物细胞生长的影响

对分别从中华芦荟、库拉索芦荟和木立芦荟叶肉组织中分离提取得到的 3种凝集素 (命名为Lec1、Lec2和Lec3)进行了理化性质的比较研究 ,考察了三者的分子质量 ,对糖抑制的专一性和糖基组成。结果表明Lec1和Lec3的相对分子质量为2 3 0 0 0 ,而Lec2为 2 6 0 0 0 ,只有Lec3能被麦芽糖抑制。糖基组成分析结果表明 ,三者的糖链部分主要由甘露糖、葡萄糖和N 乙酰氨基葡萄糖构成。三种芦荟凝集素能够识别并抑制K562乳腺癌细胞的生长 ,中华凝集素、库拉索凝集素、木立凝集素的抑瘤率IC50值分别为 4 1 93、2 30 5、1 41 8mg/ml。而在质量浓度 >2 5mg/ml时它们对成纤维细胞FC的生长有一定的促进作用。动物体内实验进一步证实了芦荟凝集素的抑瘤作用 ,同时表明芦荟凝集素能够激发机体的免疫功能来抵御癌细胞的入侵

Characterization of lectins from aloe species and their influences on growth of animal cells

Properties of phisico chemistry of lectins (named as Lec1,Lec2 and Lec3 respectively) from A.chinensis,A.barbadensis and A.arborescens were studied and compared by molecular weight,carbohydrate binding specificity and glycoside composition.Results show that among them only Lec3 with relative molecular mass of 23 000 while Lec2 only 26 000 can be inhibited by maltose.Glycoside of lectins is mainly composed of D mannose, D glucose and N GlcNAc.Lectins from aloe has the ability of recognising K562 tumor cells and inhibiting their growth.Lec3 has stronger inhibitive activity(IC50=1 418 mg/ml) than Lec1 (IC50=4 193 mg/ml) and Lec2 (IC50=2 305 mg/ml).These lectins show promoting effect on the growth of FC cells at high concentration.Anti tumor effect of aloe lectins was further proved by animal experiment.The results show lectins from aloe can prevent the invasion of tumor cells by activating the immunity system of the living organisms.