Solution conformation and flexibility of capsular polysaccharides from Neisseria meningitidis and glycoconjugates with the tetanus toxoid protein
Solution conformation and flexibility of capsular polysaccharides from Neisseria meningitidis and glycoconjugates with the tetanus toxoid protein
复制标题
DOI：
10.1038/srep35588
复制
发表时间：
2016-10-26
影响因子：
4.6
通讯作者：
Harding, Stephen E.
中科院分区：
文献类型：
--
作者：
Abdelhameed, Ali Saber;Morris, Gordon A.;Harding, Stephen E.
脑膜炎球菌天然的、微流化的和活化的荚膜多糖及其糖缀合物的结构完整性-以与其作为疫苗的潜在用途最相关的形式（稀释溶液）-已经就其均匀性、构象和柔性进行了研究。沉降速度分析表明，多糖的大小分布通常是双峰的，有一些证据表明，在较高的浓度较高的摩尔质量形式。活化多糖的重均摩尔质量M-w较低。然而，与破伤风类毒素蛋白的缀合大大增加了最终缀合物的摩尔质量和多分散性。通过沉降平衡“SEDFIT MSTAR”分析证实，糖缀合物具有近似单峰对数正态但宽且大的摩尔质量分布。使用HYDFIT（其全面结合沉降和粘度数据）、“构象分区”和Wales-van Holde方法的构象分析显示出高度的灵活性-至少与未缀合的多糖一样大，并且与用于缀合的破伤风类毒素（TT）蛋白非常不同。与最近发表的Hib-TT复合物的发现一样，碳水化合物组分决定了这些糖缀合物的溶液行为，尽管较低的特性粘度表明蛋白质周围的碳水化合物链具有一定程度的压缩。
The structural integrity of meningococcal native, micro-fluidized and activated capsular polysaccharides and their glycoconjugates - in the form most relevant to their potential use as vaccines (dilute solution) have been investigated with respect to their homogeneity, conformation and flexibility. Sedimentation velocity analysis showed that the polysaccharide size distributions were generally bimodal with some evidence for higher molar mass forms at higher concentration. Weight average molar masses M-w where lower for activated polysaccharides. Conjugation with tetanus toxoid protein however greatly increased the molar mass and polydispersity of the final conjugates. Glycoconjugates had an approximately unimodal log-normal but broad and large molar mass profiles, confirmed by sedimentation equilibrium "SEDFIT MSTAR" analysis. Conformation analysis using HYDFIT (which globally combines sedimentation and viscosity data), "Conformation Zoning" and Wales-van Holde approaches showed a high degree of flexibility - at least as great as the unconjugated polysaccharides, and very different from the tetanus toxoid (TT) protein used for the conjugation. As with the recently published finding for Hib-TT complexes, it is the carbohydrate component that dictates the solution behaviour of these glycoconjugates, although the lower intrinsic viscosities suggest some degree of compaction of the carbohydrate chains around the protein.