新型隐球菌完整细胞中莢膜原位组成和相互作用检测的固体核磁共振新方法

新型隐球菌是一种伺机致感染真菌，每年在全球造成至少100万人感染，死亡率约62%。莢膜是以多糖为主要成分的位于细胞壁外侧的一层特殊结构，是新型隐球菌的毒力因子之一和重要的药物靶标。由于现有技术和分析方法的不足，至今对莢膜组成、结构和相互作用等多方面性质的了解都十分有限。本项目拟围绕新型隐球菌完整细胞展开，从莢膜组成与结构特征、莢膜内部各组分以及莢膜与其他细胞器间相互作用两个研究角度，系统地发展优化一系列研究完整细胞中莢膜结构的固体核磁共振新技术和新方法，包括：调试优化现有固体核磁共振脉冲程序实现对完整细胞这一复杂体系分析检测和数据分析的方法；发展新型固体核磁共振针对CH2基团选择性脉冲技术；发展利用顺磁驰豫增强效应获取完整细胞中各组分相互作用信息的方法。本研究工作将为莢膜领域的研究提供新技术方法，也将深化对新型隐球菌莢膜组成、结构与相互作用等方向的认识，为抗真菌药物的开发提供有价值的信息。

Cryptococcus neoformans is an opportunistic fungal pathogen. It causes more than one million infections globally every year, the estimated mortality rate is 62%. The capsule is a specialized layer surrounding the cell wall and composed of mostly polysaccharides, it is one of the major virulent factors of C. neoformans, and serves as an important drug target. Due to the limitations of current techniques and analytical methods, the composition, structure and interactions of the capsule are not well studied. This proposal plans to use the whole cell of C. neoformans as the platform to investigate the capsule from two directions (1) composition and structural features, and (2) interactions within the capsule and with other structural layers. The ultimate goal is to systematically develop and optimize a series of new techniques and methods of solid state NMR to survey the capsule in the whole cell, including: optimizing the current solid state NMR pulse sequences to adapt to the new and sophisticated system of the intact cell of C. neoformans and accomplish the tasks of signal detection and data analysis; developing new solid state NMR pulse sequences with CH2 group selectivity; developing new methods utilizing paramagnetic relaxation enhancement to acquire the information of the interactions between the components of the intact cell. The work will provide new techniques and methods to the research area of the capsule, it will also expand the current understandings of the compositions, the structure and the interactions of the capsule, and shed light on the development of new antifungal drugs.