Sun Xinyu, Li Dong, Wang Zhaoshuai, Yin Panchao, Hu Rundong, Li Hui, Liu Qiao, Gao Yunyi, Ren Baiping, Zheng Jie, Wei Yinan, Liu Tianbo
Department of Polymer Science and Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325, United States.
Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506, United States.
ACS Omega. 2018 Apr 20;3(4):4384-4391. doi: 10.1021/acsomega.8b00021. eCollection 2018 Apr 30.
The role of electrostatic interactions in the viral capsid assembly process was studied by comparing the assembly process of a truncated hepatitis B virus capsid protein Cp149 with its mutant protein D2N/D4N, which has the same conformational structure but four fewer charges per dimer. The capsid protein self-assembly was investigated under a wide range of protein surface charge densities by changing the protein concentration, buffer pH, and solution ionic strength. Lowering the protein charge density favored the capsid formation. However, lowering charge beyond a certain point resulted in capsid aggregation and precipitation. Interestingly, both the wild-type and D2N/D4N mutant displayed identical assembly profiles when their charge densities matched each other. These results indicated that the charge density was optimized by nature to ensure an efficient and effective capsid proliferation under the physiological pH and ionic strength.
通过比较截短的乙型肝炎病毒衣壳蛋白Cp149与其突变蛋白D2N/D4N的组装过程，研究了静电相互作用在病毒衣壳组装过程中的作用。突变蛋白D2N/D4N具有相同的构象结构，但每个二聚体的电荷少四个。通过改变蛋白质浓度、缓冲液pH值和溶液离子强度，在广泛的蛋白质表面电荷密度范围内研究了衣壳蛋白的自组装。降低蛋白质电荷密度有利于衣壳形成。然而，电荷降低到一定程度后会导致衣壳聚集和沉淀。有趣的是，当野生型和D2N/D4N突变体的电荷密度相互匹配时，它们显示出相同的组装图谱。这些结果表明，电荷密度在生理pH值和离子强度下通过自然优化，以确保高效且有效的衣壳增殖。
