Impact of Assembly State on the Defect Tolerance of TMV-Based Light Harvesting Arrays
Impact of Assembly State on the Defect Tolerance of TMV-Based Light Harvesting Arrays
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DOI：
10.1021/ja909566z
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发表时间：
2010-05-05
影响因子：
15
通讯作者：
Francis, Matthew B.
中科院分区：
文献类型：
--
作者：
Miller, Rebekah A.;Stephanopoulos, Nicholas;Francis, Matthew B.
有机发色团的自组装捕光阵列可以使用烟草花叶病毒外壳蛋白（TMVP）作为模板。含有高比例的供体受体的系统内的能量转移的效率表现出强烈的依赖于TMVP组装状态。来自发色团标记的蛋白质的单一库存的杆和盘组件表现出显着不同的能量转移水平，与杆显着优于磁盘。通过将光惰性缀合物受控地引入组装体中来探索上级转移效率的起源。的杆的效率表现出线性依赖于失活的发色团的比例，这表明冗余的能量转移途径，可以绕过缺陷位点的可用性。类似的基于磁盘的系统在所有缺陷级别上的效率都明显较低。为了进一步检查这些差异，测量了仅供体系统的亮度作为缺陷掺入的函数。在棒组件中，供体发色团的光物理性质表现出显着的依赖于缺陷的数量。这些差异可以部分归因于杆中的垂直能量转移事件比盘中的水平转移发生得更快。使用这些几何形状和先前测量的能量传递速率，开发了计算模型，以更详细地了解这种行为，并指导未来系统的优化。这些模拟表明，激发态耗散率的显着差异可能也有助于更高的效率的棒和组装过程中的统计变化发挥更小的作用。
Self-assembling, light harvesting arrays of organic chromophores can be templated using the tobacco mosaic virus coat protein (TMVP). The efficiency of energy transfer within systems containing a high ratio of donors to acceptors shows a strong dependence on the TMVP assembly state. Rod and disk assemblies derived from a single stock of chromophore-labeled protein exhibit drastically different levels of energy transfer, with rods significantly outperforming disks. The origin of the superior transfer efficiency was probed through the controlled introduction of photoinactive conjugates into the assemblies. The efficiency of the rods showed a linear dependence on the proportion of deactivated chromophores, suggesting the availability of redundant energy transfer pathways that can circumvent defect sites. Similar disk-based systems were markedly less efficient at all defect levels. To examine these differences further, the brightness of donor-only systems was measured as a function of defect incorporation. In rod assemblies, the photophysical properties of the donor chromophores showed a significant dependence on the number of defects. These differences can be partly attributed to vertical energy transfer events in rods that occur more rapidly than the horizontal transfers in disks. Using these geometries and the previously measured energy transfer rates, computational models were developed to understand this behavior in more detail and to guide the optimization of future systems. These simulations have revealed that significant differences in excited state dissipation rates likely also contribute to the greater efficiency of the rods and that statistical variations in the assembly process play a more minor role.