Zhang Ying, Chu Qianjin, Du Luchao, Yao Yugui, Chen Hailong, Wang Peng, Zhang Jianping, Chen Mingqing, Peng Lingfeng, Weng Yuxiang
Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
Institute of Physics, Chinese Academy of Sciences, Beijing, China.
Biophys J. 2025 Jul 15;124(14):2317-2326. doi: 10.1016/j.bpj.2025.06.004. Epub 2025 Jun 7.
The photosynthetic bacterial light-harvesting antenna complex 2 (LH2), consisting of ring-like bacteriochlorophylls aggregates, constitutes an optimal excitonic structure for efficient energy transfer. Any distortion from this structure would cause efficiency losses. When adapted to low-light growing conditions, LH2-embedded membranes form vesicles to enhance light capture, albeit at the expense of curvature-induced LH2 deformation. Therefore, evolution should optimize vesicle sizes for overall light utilization efficiency. To unveil this optimization strategy, LH2 was assembled onto silica nanoparticles of a wide size region to simulate LH2 deformation, which was characterized by the B850 lifetime both theoretically and experimentally. We found that LH2 was undeformed only within the size range of 50-80 nm, akin to vesicle sizes observed in bacteria, suggesting that vesicle size optimization follows the LH2 structural design principle.
光合细菌捕光天线复合体2（LH2）由环状细菌叶绿素聚集体组成，是实现高效能量转移的最佳激子结构。该结构的任何畸变都会导致效率损失。当适应低光照生长条件时，嵌入LH2的膜会形成囊泡以增强光捕获，尽管这是以曲率诱导的LH2变形为代价的。因此，进化应该针对整体光利用效率优化囊泡大小。为了揭示这种优化策略，将LH2组装到宽尺寸范围的二氧化硅纳米颗粒上以模拟LH2变形，通过理论和实验手段利用B850寿命对其进行表征。我们发现，LH2仅在50 - 80纳米的尺寸范围内未发生变形，这与在细菌中观察到的囊泡大小相似，表明囊泡大小优化遵循LH2结构设计原则。
