SNAP25相分离过程中蛋白质结构、相互作用以及稳定性的核磁共振波谱研究

无膜细胞器是细胞内某些蛋白质或者核酸发生相分离而形成的液滴。已有的研究表明相分离在细胞中广泛存在，相分离的失调通常与一些神经退行性疾病相关。对于相分离形成的分子机制以及相分离过程中蛋白质构象的变化的研究对理解蛋白质的聚集机制以及由聚集所导致疾病的发病机理至关重要。SNAP25蛋白是人体内广泛分布的蛋白质，我们发现SNAP25蛋白在体外会发生相分离。目前对SNAP25发生相分离的分子机制仍不清楚。本项目拟运用常规以及19F核磁共振波谱方法研究SNAP25发生相分离过程中SNAP25结构变化、相互作用信息以及相分离液滴中SH3蛋白的稳定性,理解SNAP25发生相分离的分子机制，为SNAP25形成相分离的生物学功能研究打下基础。19F NMR研究相分离具有广泛的应用性，能推广到其他类型的相分离系统（蛋白质、RNA）研究中。

Membraneless organelles are droplets formed by the phase separations of certain proteins or nucleic acids inside cells. Previous studies have revealed that phase separations exist extensively in cells. Dysfunctions of phase separations are often associated with some neurodegenerative diseases. The study on molecular mechanisms of phase separation and protein conformational changes during phase separation are critical for understanding the mechanism of protein aggregation and the pathogenesis of diseases caused by aggregation. The SNAP25 protein is a widely distributed protein in humans. We found that SNAP25 protein underwent phase separation in vitro. The molecular mechanism of phase separation of SNAP25 remains unclear. This project intends to use conventional and 19F NMR spectroscopy methods to study the structural changes and protein interactions of SNAP25 and probe SH3 stability in phase-separated droplets during phase separation of SNAP25. We seek to study conformational changes and protein interactions at the atomic level and explore the role of these changes and interaction in phase separation process. We hope this study would contribute to the molecular mechanism understanding of SNAP25 phase separation and lay a foundation for the study on the biological function of SNAP25 phase separation. 19F NMR studies on phase separation have a wide range of applications and will be applied to the study of other phase separation systems (protein and RNA).