Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720-1460, USA.
Nano Lett. 2010 Jan;10(1):181-6. doi: 10.1021/nl9032395.
The protein coat of the tobacco mosaic virus (TMV) has been explored extensively for the construction of nanoscale architectures. In previous work, we have reported efficient TMV-based light harvesting systems bearing chromophores in a hollow channel of the assembled protein. We have also reported an N-terminal transamination/oximation method that could be used to attach electrodes and catalytic groups to the exterior surface of the rods. To complement these techniques, we report herein a new circular permutant of the TMV capsid protein that repositions the N- and C-termini to the center of the assemblies. This protein can be produced in very high yield through E. coli expression and self-assembles into light harvesting rods that are much like those assembled from the wild-type protein. However, the disks formed from the permutant structure are stable over a significantly wider pH range, greatly improving the practicality of this assembled form for materials applications. The new position of the N-terminus allows functional groups to be installed in the inner pore of the disks, affording geometries reminiscent of natural photosynthetic systems. The permutant also shows the ability to coassemble with regular monomers, allowing the future generation of multicomponent rod structures that are modified on the exterior and interior surfaces, as well as in the internal RNA channel.
烟草花叶病毒（TMV）的蛋白质外壳被广泛探索用于构建纳米级架构。在之前的工作中，我们已经报道了在组装蛋白的中空通道中带有生色团的高效 TMV 基光收集系统。我们还报道了一种 N 端转氨/肟化方法，可用于将电极和催化基团连接到棒的外表面。为了补充这些技术，我们在此报告了 TMV 衣壳蛋白的一种新的环状变构体，它将 N 和 C 末端重新定位到组装体的中心。这种蛋白质可以通过大肠杆菌表达以非常高的产量生产，并自组装成光收集棒，这些棒与从野生型蛋白组装的棒非常相似。然而，由变构体结构形成的盘在更宽的 pH 范围内稳定，极大地提高了这种组装形式在材料应用中的实用性。N 末端的新位置允许在盘的内孔中安装官能团，提供类似于天然光合作用系统的几何形状。变构体还显示出与规则单体共组装的能力，允许未来生成在外部和内部表面以及内部 RNA 通道上进行修饰的多组分棒状结构。
