Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France.
Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
J Phys Chem B. 2020 Nov 12;124(45):9987-9995. doi: 10.1021/acs.jpcb.0c05024. Epub 2020 Nov 2.
As with many protein multimers studied in biophysics, the assembly and disassembly dynamical pathways of hepatitis B virus (HBV) capsid proteins are not symmetrical. Using time-resolved small-angle X-ray scattering and singular value decomposition analysis, we have investigated these processes by a rapid change of salinity or chaotropicity. Along the assembly pathway, the classical nucleation-growth mechanism is followed by a slow relaxation phase during which capsid-like transient species self-organize in accordance with the theoretical prediction that the capture of the few last subunits is slow. By contrast, the disassembly proceeds through unexpected, fractal-branched clusters of subunits that eventually vanish over a much longer time scale. On the one hand, our findings confirm and extend previous views as to the hysteresis phenomena observed and theorized in capsid formation and dissociation. On the other hand, they uncover specifics that may directly relate to the functions of HBV subunits in the viral cycle.
与生物物理学中研究的许多蛋白质多聚体一样，乙型肝炎病毒 (HBV) 衣壳蛋白的组装和拆卸动态途径不对称。使用时间分辨小角度 X 射线散射和奇异值分解分析，我们通过快速改变盐度或变构性来研究这些过程。在组装途径中，遵循经典的成核-生长机制，然后是缓慢松弛阶段，在此期间，衣壳样瞬态物质根据理论预测进行自组织，即捕获最后几个亚基的速度较慢。相比之下，组装通过意想不到的、分形分支的亚基簇进行，最终在更长的时间尺度上消失。一方面，我们的发现证实并扩展了以前关于衣壳形成和解离中观察到和理论化的滞后现象的观点。另一方面，它们揭示了可能与 HBV 亚基在病毒周期中的功能直接相关的细节。
