海洋真菌多糖YCP的酶法降解及其产物分析

Enzymatic degradation of marine polysaccharide YCP and analysis of YCP-derived fragments

目的:研究海洋真菌多糖YCP经酶法降解后理化性质及免疫活性的改变,探讨其结构和活性之间的关系。方法:采用人唾液α-淀粉酶降解海洋真菌多糖YCP,经凝胶色谱分离纯化;通过HPLC、红外光谱以及薄层色谱等对其理化性质进行分析;通过小鼠腹腔巨噬细胞NO诱生实验,中性红吞噬实验以及与巨噬细胞表面YCP相关受体竞争性结合实验分析其免疫活性的改变。结果:海洋真菌多糖YCP经人唾液α-淀粉酶降解后得到相对分子质量约为6.6×103的单一组分,该组分的单糖组成以及红外光谱特征与YCP相同,对巨噬细胞分泌NO以及吞噬中性红的能力没有显著的促进作用,对YCP与巨噬细胞表面相关受体的结合几乎不产生抑制作用。结论:海洋真菌多糖YCP经人唾液α-淀粉酶部分降解后免疫活性显著降低,说明YCP的完整分子可能对维持YCP的免疫活性具有重要作用。

Aim：To explore the relationship between structure and immunological activity of marine polysaccharide YCP,the physicochemical property and immunological activity of the YCP-derived fragment were studied.Methods：YCP was hydrolyzed by α-amylase from human saliva.The hydrolysate was purified to obtain an polysaccharide fragment by gel filtration chromatography.The physicochemical properties of this YCP-derived fragment was characterized by HPLC,FT-IR and TLC.In addition,changes of phagocytic activity,production of reactive nitrogen and macrophage binding were investigated.Results：The relative molecular weight of YCP-derived fragment was approximately 6.6×103.The monosaccharide composition and FT-IR of the YCP-derived fragment were identical to YCP.No significant effect of the YCP-derived fragment on NO production and murine macrophage phagocyte were observed.And this fragment was not able to compete the binding between YCP and macrophages.Conclusion：The remarkable decrease of immunological activity of YCP-derived fragments degraded by α-amylase of human saliva suggests that the complete structure and high molecule weight of YCP are essential for its immuno-modulatory activity.