Dekker Jan P, Germano Marta, van Roon Henny, Boekema Egbert J
Faculty of Sciences, Division of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands,
Photosynth Res. 2002;72(2):203-10. doi: 10.1023/A:1016188818591.
We studied the aggregation state of Photosystem II in stacked and unstacked thylakoid membranes from spinach after a quick and mild solubilization with the non-ionic detergent n-dodecyl-alpha,D-maltoside, followed by analysis by diode-array-assisted gel filtration chromatography and electron microscopy. The results suggest that Photosystem II (PS II) isolates either as a paired, appressed membrane fragment or as a dimeric PS II-LHC II supercomplex upon mild solubilization of stacked thylakoid membranes or PS II grana membranes, but predominantly as a core monomer upon mild solubilization of unstacked thylakoid membranes. Analysis of paired grana membrane fragments reveals that the number of PS II dimers is strongly reduced in single membranes at the margins of the grana membrane fragments. We suggest that unstacking of thylakoid membranes results in a spontaneous disintegration of the PS II-LHC II supercomplexes into separated PS II core monomers and peripheral light-harvesting complexes.
我们使用非离子去污剂正十二烷基-α-D-麦芽糖苷对菠菜的堆叠和非堆叠类囊体膜进行快速温和的增溶处理，随后通过二极管阵列辅助凝胶过滤色谱法和电子显微镜分析，研究了光系统II的聚集状态。结果表明，在对堆叠类囊体膜或PS II基粒膜进行温和增溶时，光系统II（PS II）以成对的、紧密排列的膜片段或二聚体PS II-LHC II超复合物形式分离出来，但在对非堆叠类囊体膜进行温和增溶时，主要以核心单体形式存在。对成对的基粒膜片段进行分析发现，在基粒膜片段边缘的单膜中，PS II二聚体的数量大幅减少。我们认为，类囊体膜的解堆叠会导致PS II-LHC II超复合物自发解体，形成分离的PS II核心单体和外周捕光复合物。
