Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States.
Biomacromolecules. 2013 Sep 9;14(9):2989-95. doi: 10.1021/bm400796c. Epub 2013 Aug 27.
Rational design of modifications to the interior and exterior surfaces of virus-like particles (VLPs) for future therapeutic and materials applications is based on structural information about the capsid. Existing cryo-electron microscopy-based models suggest that the C-terminus of the bacteriophage P22 coat protein (CP) extends toward the capsid exterior. Our biochemical analysis through genetic manipulations of the C-terminus supports the model where the CP C-terminus is exposed on the exterior of the P22 capsid. Capsids displaying a 6xHis tag appended to the CP C-terminus bind to a Ni affinity column, and the addition of positively or negatively charged coiled coil peptides to the capsid results in association of these capsids upon mixing. Additionally, a single cysteine appended to the CP C-terminus results in the formation of intercapsid disulfide bonds and can serve as a site for chemical modifications. Thus, the C-terminus is a powerful location for multivalent display of peptides that facilitate nanoscale assembly and capsid modification.
为了未来的治疗和材料应用，对病毒样颗粒（VLPs）的内外表面进行合理设计，这基于衣壳的结构信息。现有的基于冷冻电子显微镜的模型表明，噬菌体 P22 外壳蛋白（CP）的 C 末端向衣壳外部延伸。我们通过对 C 末端进行遗传操作的生化分析支持了这样的模型，即 CP 的 C 末端暴露在 P22 衣壳的外部。展示在 CP C 末端附加 6xHis 标签的衣壳会与 Ni 亲和柱结合，并且向衣壳中添加带正电荷或负电荷的卷曲螺旋肽会导致这些衣壳在混合时发生缔合。此外，在 CP C 末端附加一个半胱氨酸会导致衣壳间形成二硫键，并可作为化学修饰的位点。因此，C 末端是多价展示肽的有力位置，这些肽可促进纳米级组装和衣壳修饰。
