一种膜荚黄芪凝集素的分离纯化研究

Isolation and purification of a lectin from roots of Astragalus membranaceus

目的从膜荚黄芪根中分离纯化一种凝集素。方法通过硫酸铵分级沉淀和ConA-Sepharose4B亲和色谱从膜荚黄芪根浸提液中分离纯化一种凝集素。结果经过上述两步纯化得到电泳纯的凝集素,SDS-PAGE和Superdex75凝胶过滤色谱测定该凝集素的相对分子质量分别为3.15×104和3.35×104,糖蛋白染色显示其为糖蛋白,总糖的量为10.7%。结论从膜荚黄芪根中分离纯化得到一种凝集素,该蛋白为单亚基糖蛋白,具有对兔血红细胞的凝集活性,凝集活性的比活力为391.9U/mg。

Objective To isolate and purify a lectin from the roots of Astragalus membranaceus. Methods The protein was purified using a combination of 20%-60%ammonium sulfate fraction and ConA-Sepharose 4B affinity chromatography. Results The purified protein appeared as a single band with molecular mass of 3.15 × 10^4 on SDS-PAGE and the relative molecular mass was estimated by gel filtration on a calibrated Superdex 75 column with apparent molecular weight of 3.35× 10^4. This lectin was a glyco- protein with a neutral carbohydrate content of 10.7 %. Conclusion A lectin is isolated and purified from the roots of A. membranaceus for the first time. It is a monomer glycoprotein and its specific activity is 391.9 U/mg.