基于硫酸化修饰下的青钱柳多糖空间构象变化与免疫活性关系研究

Sulfation modification of polysaccharides has contributed to their distinct physicochemical properties and various biological activities has aroused widespread interest. This program is based on our previous work on the analysis of the structure and biological activity of a high purity polysaccharide from Cyclocarya paliurus (Batal.) Iljinskaja. A series sulfated polysaccharide derivatives were obtain by control the sulfation modification condition. The aim is to analyze the solid three dimension (3D) structure of purified polysaccharide by X-ray fiber diffraction and atom force microscope (AFM) combined with molecular simulation technique. The static- and dynamic- laser light scattering, size exclusion chromatography combined with LLS, atomic force microscopy (AFM), and circular dichroism (CD), the theory of polymer macromolecule diluted solution are introduced to determine molecular chain conformation of the polysaccharide fractions. At last, the computer simulation technique is used to evaluate the structure model. The relationship model established by computer simulation is verified by activity experiments in vitro to construct a computer simulation system for the study of structure-activity relationship of polysaccharide from Cyclocarya paliurus (Batal.) Iljinskaja. This program will provide theory basis and technique supports for the advanced structure analysis and structure-activity relationship study of polysaccharide compounds.

硫酸化修饰赋予多糖特殊的理化性质和广泛的生物活性，已引起研究者的广泛兴趣。本项目拟在课题组前期工作已经从青钱柳中分离获得高纯度青钱柳多糖并深入分析其结构和生物活性的基础上，通过控制青钱柳多糖的硫酸酯化过程，建立不同硫酸酯基的取代度、取代位置的青钱柳多糖硫酸化系列衍生物。通过尺寸排除色谱、动静态激光光散射、GC-MS、粘度法、圆二色光谱和原子力显微镜等现代仪器分析方法结合空间立体化学分析技术获取青钱柳多糖的固态三维结构和溶液立体构象，并采用分子模拟技术模拟其空间结构模型，最终建立固态三维结构与溶液构象综合分析多糖空间构象的研究方法；综合空间构象和免疫活性的研究结果，解析青钱柳多糖硫酸化修饰下的空间构象与免疫活性之间的关系。本项目的完成将为多糖类化合物的高级结构和构效关系研究提供理论探索，具有良好的科学性和原创性。

硫酸化修饰赋予多糖特殊的理化性质和广泛的生物活性，已引起研究者的广泛兴趣。项目从青钱柳中分离获得高纯度青钱柳多糖,通过对青钱柳多糖进行硫酸化分子修饰，获得系得青钱柳多糖的硫酸化产物。通过尺寸排除色谱、动静态激光光散射、GC-MS、粘度法和原子力显微镜等现代仪器分析方法获取多糖组分的主要理化性质及结构，以小鼠巨噬细胞株RAW264.7细胞为研究对象，探讨了青钱柳多糖及其修饰后产物对巨噬细胞功能的影响。结果发现，青钱柳多糖及其修饰后产物均能够显著促进巨噬细胞增殖，无细胞毒性；增强细胞吞噬功能；上调活性氧NO及细胞因子肿瘤坏死因子TNF-α、白细胞介素-6、白细胞介素-1β的分泌，进一步利用PCR和Western blot技术从细胞因子mRNA水平、iNOS蛋白水平论证青钱柳多糖及其修饰后产物对细胞因子及活性氧的释放是在翻译、转录水平调控的。综合结构和免疫活性的研究结果，解析青钱柳多糖硫酸化修饰下的结构与免疫活性之间的关系。本项目的完成将为多糖类化合物的高级结构和构效关系研究提供理论探索。