Watching the Native Supramolecular Architecture of Photosynthetic Membrane in Red Algae TOPOGRAPHY OF PHYCOBILISOMES AND THEIR CROWDING, DIVERSE DISTRIBUTION PATTERNS
Watching the Native Supramolecular Architecture of Photosynthetic Membrane in Red Algae TOPOGRAPHY OF PHYCOBILISOMES AND THEIR CROWDING, DIVERSE DISTRIBUTION PATTERNS
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DOI：
10.1074/jbc.m805114200
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发表时间：
2008-12-12
影响因子：
4.8
通讯作者：
Zhang, Yu-Zhong
中科院分区：
文献类型：
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作者：
Liu, Lu-Ning;Aartsma, Thijs J.;Zhang, Yu-Zhong
整个光合膜网络的结构在超分子水平上决定了光合蛋白复合物的生理作用。到目前为止，红藻类囊体的天然构型的精确图像仍然缺乏。在这项工作中，我们研究了超分子结构的藻胆体（PBsome）和天然类囊体膜从单细胞的红色紫球藻，利用原子力显微镜（AFM）和透射电子显微镜。单个PBsome的地形，其特征在于通过原子力显微镜成像分离和膜结合PBsome复合物。类囊体膜的天然结构表现为PBsome在膜表面的可变排列。这表明，不同的光照条件下，紫球藻光合膜上的PBsome呈随机排列或有序排列。此外，PBsome在膜表面的分布大多是拥挤的。这是第一次利用原子力显微镜观察紫球藻PBsome的天然结构及其在类囊体膜上的拥挤分布。不同光环境下PBsome的不同分布模式表明类囊体膜的光适应性，可能提高了能量收集效率。这些结果为研究红藻PBsome的超分子结构和体内类囊体膜的多样性提供了重要线索。
The architecture of the entire photosynthetic membrane network determines, at the supramolecular level, the physiological roles of the photosynthetic protein complexes involved. So far, a precise picture of the native configuration of red algal thylakoids is still lacking. In this work, we investigated the supramolecular architectures of phycobilisomes (PBsomes) and native thylakoid membranes from the unicellular red alga Porphyridium cruentum using atomic force microscopy (AFM) and transmission electron microscopy. The topography of single PBsomes was characterized by AFM imaging on both isolated and membrane-combined PBsomes complexes. The native organization of thylakoid membranes presented variable arrangements of PBsomes on the membrane surface. It indicates that different light illuminations during growth allow diverse distribution of PBsomes upon the isolated photosynthetic membranes from P. cruentum, random arrangement or rather ordered arrays, to be observed. Furthermore, the distributions of PBsomes on the membrane surfaces are mostly crowded. This is the first investigation using AFM to visualize the native architecture of PBsomes and their crowding distribution on the thylakoid membrane from P. cruentum. Various distribution patterns of PBsomes under different light conditions indicate the photoadaptation of thylakoid membranes, probably promoting the energy-harvesting efficiency. These results provide important clues on the supramolecular architecture of red algal PBsomes and the diverse organizations of thylakoid membranes in vivo.