海参高硫酸化寡糖的制备、结构及其对Aβ诱导的神经元毒性的保护机制研究

项目名称： 海参高硫酸化寡糖的制备、结构及其对Aβ诱导的神经元毒性的保护机制研究

项目编号： No.31301417

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 陈士国

作者单位： 浙江大学

项目金额： 24万元

中文摘要： 食源性酸性多糖的神经保护活性近年来已广有报道，然而受限于多糖结构的复杂性和结构分析技术的滞后，其构效机理目前仍不清楚。 本研究以课题组前期从海参中纯化鉴定的三种具重复序列结构的硫酸多糖为对象，利用氧化降解、酸降解以及色谱纯化技术制备系列寡糖，并结合质谱和高分辨核磁共振技术鉴定其结构；应用氧化应激损伤神经细胞模型，研究寡糖硫酸基取代方式、分子量、支链取代基对其神经保护活性的影响；在此基础上，以Aβ诱导的海马神经细胞损伤模型，以Aβ蛋白聚集状态和BACE1酶活变化为切入点，阐明海参寡糖对神经细胞保护机制；并以计算机模拟、SPR技术研究Aβ分子上的硫酸寡糖结合区域，圆二色谱和原子力显微镜技术明确寡糖结构对Aβ处理过程中二级结构的影响，阐明寡糖靶向Aβ机制和构效机理。 本课题的研究成果不仅将为食源性硫酸寡糖抗老年痴呆活性的构效机理研究探索共性规律，也为食品加工过程多糖分子量的控制等提供理论依据。

中文关键词： 硫酸多糖；降解；老年痴呆症；构效关系；

英文摘要： Food-derived acid polysaccharides have been widely reported to have neuron-protective activity. However, as the complexity of the polysaccharides structure and limitation in structure analytical skills, the structure-activity relationship was still unclear. This study was based on three sulfated polysaccharides with well-repeated units, which were identified from sea cucumber in our previously research. The oligosaccharides of these polysaccharides were prepared either by oxidative degradation or acid degradation, and then purified by geltration followed with SAX-HPLC. The structures of these oligosaccharides were identified by combination of mass spectrometry and high-resolution nuclear magnetic resonance technology. The neuron-protection activities of the oligosaccharides were firstly tested by an oxidative stress damage cell model, which was to investigate the effect of the sulfation pattern, molecular size, and branched chain on the neuron-protective activity.Then, the exact neuron-protection mechanism of the oligosaccharides was further tested by an Aβ-induced nerve cell damage model, the cell viability as well as the changes in Aβ aggregation state and BACE1 activity were tested to evaluate the activities; finally, to clarify the mechanism of the interaction mechanisms and structure-activity relationship,

英文关键词： sulfated polysaccharide；depolymerization；Alzheimer's Disease；structure-activity relationship；