Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Science, Wuhan, 430071, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
J Phys Chem Lett. 2022 Aug 25;13(33):7804-7808. doi: 10.1021/acs.jpclett.2c01920. Epub 2022 Aug 17.
The phenomenon of liquid-liquid phase separation is found in numerous biological processes. The biomolecules enveloped in the phase-separated droplets experience an obviously different environment from those in cellular or aqueous solution. Herein, we quantitatively characterized the thermodynamics and exchange kinetics of a model protein SH3 domain in the condensed phase of an intrinsically disordered region of a germ cell-specific protein DDX4N1 by using F-NMR spectroscopy. The stability and exchange rate of the SH3 domain are different from those in buffer and macromolecular crowding conditions. Our finding indicates that the local transient ordered microstructure and heterogeneity in the condensates play significant roles in modulating the biophysical properties of the enveloped proteins, and this finding may be essential to further our understanding how phase separation regulates the function of proteins in cells.
液-液相分离现象存在于许多生物过程中。被包裹在相分离液滴中的生物分子所处的环境与细胞内或水溶液中的环境明显不同。在此，我们通过使用 F-NMR 光谱法，定量表征了模型蛋白 SH3 结构域在生殖细胞特异性蛋白 DDX4N1 的无规则区域的凝聚相中热动力学和交换动力学。SH3 结构域的稳定性和交换速率与缓冲液和大分子拥挤条件下的稳定性和交换速率不同。我们的发现表明，凝聚体中局部瞬态有序的微观结构和异质性在调节包裹蛋白的生物物理特性方面起着重要作用，这一发现可能对于进一步理解相分离如何调节细胞内蛋白质的功能至关重要。
