条斑紫菜凝集素的提取及其性质研究(摘要)(英文)

目的]研究条斑紫菜(Porphyra yezoensis)凝集素的提取及分离纯化条件,并测定凝集素的性质。方法]以比活力为指标,研究了缓冲体系、固液比、温度及时间等条件对条斑紫菜凝集素提取效果的影响。采用DEAE-Sepharose FF离子交换层析技术进行分离,确定了分离的最佳条件。以血凝集活性为指标,测定了凝集素的糖专一性、二价阳离子依赖性、温度及酸碱稳定性等性质。结果]固液比为1∶5的Tris-HCl(25mmol/L,pH值7.5)缓冲液在40℃条件下提取20h得到的提取液具有最高的比活力。条斑紫菜凝集素在50℃条件下加热30min后活性保持不变,表现出一定的热稳定性,最适作用pH值为7～9。该凝集素能够与麦芽糖、半乳糖、阿拉伯糖及木糖结合,其中与麦芽糖的结合最强,凝集活性依赖Ca2+、Mg2+等二价阳离子。结论]该研究为阐明条斑紫菜的免疫机制及其高效综合利用提供了理论依据。

Researches on Extraction,Purification Technique and Properties of Lectin from Porphyra yezoensis

Objective] The aim was to explore the extraction technique and purification method of lectin from Porpya yezoensis,as well as to investigate the properties of lectin. Method] The effects of four factors such as buffer system,solid-liquid ratio,temperature,and extracting time on the lectin extraction result from P. yezoensis were investigated by the use of specific activity as the indicator. Then the lectin was purified by DEAE-Sepharose FF chromatography. The hemagglutination activity was used as the indicator,and the properties of the lectin such as carbohydrate specificity,divalent cations dependence,temperature,acidic and alkaline stability and others were detected. Result] The optimal extraction conditions were：extraction ageat Tris-HCl buffer （25 mmol/L,pH=7.5 ）,solid-liquid ratio of 1：5,extracting temperature of 40 ℃,and extracting time of 16 h. The activity of the lectin of P. yezoensis didn＇t change after 30 min of being heated at 50 ℃,which showed a certain extent of thermal stability,and the suitable pH value was 7-9. The lectin of P. yezoensis could combine with maltose,D-galactose,D-xylose and L-Arabinose,in which the binding force with the maltose was the strongest. The lectin activity was depended on the addition of Ca2＋ and Mg2＋. Conclusion] The research had provided theoretical basis for the clarification of immune mechanism of P. yezoensis,as well as its high effective utilization.