Bio-Organic Chemistry Research Group, Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands.
Department of Physics and Astronomy, University of California, Riverside, California 92521, United States.
J Am Chem Soc. 2022 Jul 20;144(28):12608-12612. doi: 10.1021/jacs.2c04074. Epub 2022 Jul 6.
Cowpea chlorotic mottle virus (CCMV) is a widely used model for virus replication studies. A major challenge lies in distinguishing between the roles of the interaction between coat proteins and that between the coat proteins and the viral RNA in assembly and disassembly processes. Here, we report on the spontaneous and reversible size conversion of the empty capsids of a CCMV capsid protein functionalized with a hydrophobic elastin-like polypeptide which occurs following a pH jump. We monitor the concentrations of = 3 and = 1 capsids as a function of time and show that the time evolution of the conversion from one number to another is not symmetric: The conversion from = 1 to = 3 is a factor of 10 slower than that of = 3 to = 1. We explain our experimental findings using a simple model based on classical nucleation theory applied to virus capsids, in which we account for the change in the free protein concentration, as the different types of shells assemble and disassemble by shedding or absorbing single protein subunits. As far as we are aware, this is the first study confirming that both the assembly and disassembly of viruslike shells can be explained through classical nucleation theory, reproducing quantitatively results from time-resolved experiments.
豇豆花叶病毒（CCMV）是一种广泛用于病毒复制研究的模型。主要的挑战在于区分外壳蛋白之间的相互作用以及外壳蛋白与病毒 RNA 之间的相互作用在组装和拆卸过程中的作用。在这里，我们报告了带有疏水性弹性蛋白样多肽的 CCMV 外壳蛋白的空衣壳的自发和可逆的尺寸转换，该转换在 pH 跃变后发生。我们监测了 = 3 和 = 1 衣壳的浓度随时间的变化，并表明从一种 number 到另一种的转换的时间演化不是对称的：从 = 1 到 = 3 的转换比从 = 3 到 = 1 的转换慢 10 倍。我们使用基于经典成核理论的简单模型来解释我们的实验结果，该模型适用于病毒衣壳，其中我们考虑了自由蛋白质浓度的变化，因为不同类型的壳通过脱落或吸收单个蛋白质亚基而组装和拆卸。据我们所知，这是第一项通过经典成核理论证实病毒样壳的组装和拆卸都可以解释的研究，定量再现了时间分辨实验的结果。
