刀豆凝集素的血凝活性及其性质研究

[目的]为进一步研究刀豆凝集素提供依据。[方法]从豆科植物刀豆属(Canavalia)中Canavalia ensiformis(L.)DC的干燥成熟种子中提取刀豆凝集素(Concanavalin A,简称ConA),进行血凝活性测定,并对其部分性质作了初步研究。[结果]结果表明:采用胰蛋白酶修饰人血(A型)红细胞来检测ConA凝集活性时,发现其活性提高了8倍。ConA对人A、B、O、AB型及供血动物(兔,鸡,鸭,鸽,鲤、鲫鱼)的血红细胞都具有一定程度的凝集活性,无供体细胞专一性或血型专一性;D-葡萄糖和D-甘露糖是ConA的专一性结合糖。ConA是一种对热较稳定的凝集素,40℃以下时ConA很稳定,80℃以上保温20 min后,血凝活性完全丧失。在pH值范围5.8~8.3,ConA的凝集活性较高,在pH>11.9时,凝集活性完全丧失。变性剂脲浓度达到0.4 mol/L以上时,ConA的凝集活性可完全丧失。[结论]该研究对今后系统阐明其生物学作用,扩大应用范围具有重要意义。

Study on Determination of Hegglutination Ativity of the Lectin from Canavalia ensiformis (L.)DC and its Characteristics

[Objective] The aim of this research was to provide the base for studying the lectin from Canavalia ensiformis(L.) DC.[Method] The concanavalin A(ConA)was extracted from the dry mature seed of C.ensiformis(L.) DC,its hegglutination activity was determined and its part characteristics were studied.[Result] It as found the agglutinative activity of ConA could increase 8 times when detected with human red cell treated by typsin.ConA can agglutinate A、B、O and AB types of human blood and the erythrocytes of rabbit, chicken,duck,pigeon,common carp and crucian carp,without sepicificity of erythocyte agglutination.D-Glucose and D-Mannose were just the sugar which could band ConA specifically.ConA was a kind of lectin stable to heat treatment.It was stable at below 40 ℃,but it was completely inactive at above 80 ℃ for 20 min.ConA had higher lectin activity at pH of 5.8～8.3,but its lectin activity was inactive at pH above 11.9.The lectin activity of ConA was completely inactive when the denaturant urea concentration reached over 4 mol/L.[Conclusion] This study has important meaning for clarifying the biology function of ConA systematically in future and enlarging its application range.