Applied Physics Department, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel.
The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat-Ram, Jerusalem, 9190401, Israel.
Photosynth Res. 2017 Oct;134(1):39-49. doi: 10.1007/s11120-017-0406-7. Epub 2017 Jun 2.
Cyanobacteria light-harvesting complexes can change their structure to cope with fluctuating environmental conditions. Studying in vivo structural changes is difficult owing to complexities imposed by the cellular environment. Mimicking this system in vitro is challenging, as well. The in vivo system is highly concentrated, and handling similar in vitro concentrated samples optically is difficult because of high absorption. In this research, we mapped the cyanobacteria antennas self-assembly pathways using highly concentrated solutions of phycocyanin (PC) that mimic the in vivo condition. PC was isolated from the thermophilic cyanobacterium Thermosynechococcus vulcanus and measured by several methods. PC has three oligomeric states: hexamer, trimer, and monomer. We showed that the oligomeric state was changed upon increase of PC solution concentration. This oligomerization mechanism may enable photosynthetic organisms to adapt their light-harvesting system to a wide range of environmental conditions.
蓝藻的光捕获复合物可以改变其结构以适应不断变化的环境条件。由于细胞环境带来的复杂性，研究体内结构变化是困难的。在体外模拟该系统也是具有挑战性的。体内系统的浓度非常高，由于高吸收，因此难以对类似的体外浓缩样品进行光学处理。在这项研究中，我们使用模拟体内条件的高浓度藻蓝蛋白（PC）溶液来绘制蓝藻天线的自组装途径。PC 从嗜热蓝藻 Thermosynechococcus vulcanus 中分离出来，并通过多种方法进行测量。PC 有三种寡聚态：六聚体、三聚体和单体。我们表明，随着 PC 溶液浓度的增加，寡聚态发生了变化。这种寡聚化机制可能使光合作用生物体能够将其光捕获系统适应广泛的环境条件。
