Chang Connie B, Knobler Charles M, Gelbart William M, Mason Thomas G
Department of Chemistry and Biochemistry, University of California-Los Angeles, Los Angeles, California 90095, USA.
ACS Nano. 2008 Feb;2(2):281-6. doi: 10.1021/nn700385z.
Virus-like particles are biomimetic delivery vehicles that cloak nanoscale cores inside coatings of viral capsid proteins, offering the potential for protecting their contents and targeting them to particular tissues and cells. To date, encapsidation has been demonstrated only for a relatively limited variety of core materials, such as compressible polymers and facetted nanocrystals, over a narrow range of cores sizes and of pH and ionic strength. Here, we encapsidate spherical nanodroplets of incompressible oil stabilized by adsorbed anionic surfactant using cationic capsid protein purified from cowpea chlorotic mottle virus. By imaging with transmission electron microscopy we show that, as the droplets become larger than the wild-type RNA core, the protein is forced to self-assemble into spherical shells that are not perfect icosahedra having special triangulation numbers characteristic of the Caspar-Klug hierarchy. Consequently, the distribution of protein conformations on larger droplets is significantly different than in the wild-type shell.
病毒样颗粒是一种仿生递送载体，它将纳米级核心包裹在病毒衣壳蛋白涂层内，具有保护其内容物并将其靶向特定组织和细胞的潜力。迄今为止，仅在相对有限的多种核心材料（如可压缩聚合物和多面体纳米晶体）上，在较窄的核心尺寸范围以及pH和离子强度范围内证明了衣壳化。在此，我们使用从豇豆褪绿斑驳病毒纯化的阳离子衣壳蛋白，将由吸附的阴离子表面活性剂稳定的不可压缩油的球形纳米液滴进行衣壳化。通过透射电子显微镜成像，我们表明，当液滴变得比野生型RNA核心大时，蛋白质被迫自组装成球形壳，这些壳不是具有卡斯帕 - 克卢格层级特征的特殊三角剖分数的完美二十面体。因此，较大液滴上蛋白质构象的分布与野生型壳中的分布显著不同。
