Chen Shiguo, Xu Jie, Xue Changhu, Dong Ping, Sheng Wenjing, Yu Guangli, Chai Wengang
College of Food Science and Technology, Ocean University of China, Qingdao, Shandong, China.
Glycoconj J. 2008 Jul;25(5):481-92. doi: 10.1007/s10719-007-9096-2. Epub 2008 Jan 25.
A non-sulfated polysaccharide was isolated from the ink sac of squid Ommastrephes bartrami after removal of the melanin granules. The carbohydrate sequence of this polysaccharide was assigned by negative-ion electrospray tandem mass spectrometry with collision-induced dissociation of the oligosaccharide fractions produced by partial acid hydrolysis of the polysaccharide. The structural determination was completed by NMR for assignment of anomeric configuration and confirmation of linkage information and it was unambiguously identified as a glycosaminoglycan-like polysaccharide containing a glucuronic acid-fucose (GlcA-Fuc) disaccharide repeat in the main chain and a N-acetylgalactosamine (GalNAc) branch at Fuc position 3: -3GlcAbeta1-4(GalNAcalpha1-3)Fucalpha1-. Partial hydrolysis of the polysaccharide to obtain several oligosaccharide fractions with different numbers of the repeating unit assisted the assignment. In the negative-ion tandem mass spectrometric analysis, the unique (0,2)A type fragmentation was important to establish the presence of a 4-linked fucose in the main polysaccharide chain and a GalNAc branch at the Fuc position-3 of the disaccharide repeat.
从巴氏柔鱼的墨囊中去除黑色素颗粒后分离出一种非硫酸化多糖。该多糖的碳水化合物序列通过负离子电喷雾串联质谱法确定，该方法利用多糖部分酸水解产生的寡糖馏分的碰撞诱导解离。通过核磁共振完成结构测定，以确定异头构型并确认连接信息，最终明确鉴定其为一种类糖胺聚糖多糖，其主链含有葡萄糖醛酸-岩藻糖（GlcA-Fuc）二糖重复序列，在岩藻糖第3位有一个N-乙酰半乳糖胺（GalNAc）分支：-3GlcAbeta1-4(GalNAcalpha1-3)Fucalpha1-。多糖的部分水解以获得具有不同重复单元数量的几种寡糖馏分有助于序列确定。在负离子串联质谱分析中，独特的(0,2)A型裂解对于确定主多糖链中4-连接岩藻糖的存在以及二糖重复序列中岩藻糖第3位的GalNAc分支很重要。
