Andersson B, Anderson J M
Biochim Biophys Acta. 1980 Dec 3;593(2):427-40. doi: 10.1016/0005-2728(80)90078-x.
The lateral distribution of the main chlorophyll-protein complexes between appressed and non-appressed thylakoid membranes has been studied. The reaction centre complexes of Photosystems I and II and the light-harvesting complex have been resolved by an SDS-polyacrylamide gel electrophoretic method which permits most of the chlorophyll to remain protein-bound. The analyses were applied to subchloroplast fractions shown to be derived from different thylakoid regions. Stroma thylakoids were separated from grana stacks by centrifugation following chloroplast disruption by press treatment or digitonin. Vesicles derived from the grana partitions were isolated by aqueous polymer two-phase partition. A substantial depletion in the amount of Photosystem I chlorophyll-protein complex and an enrichment in the Photosystem II reaction centre complex and the light-harvesting complex occurrred in the appressed grana partition region. The high enrichment in this fraction compared to grana stack fractions derived from press or digitonin-treatments, suggests that the grana Photosystem I is restricted mainly to the non-appressed grana end membranes and margins, and that the grana partitions possess mainly Photosystem II reaction centre complex and the light-harvesting complex. In contrast, stroma thylakoids are highly enriched in the Photosystem I reaction centre complex. They possess also some 10--20% of the total Photosystem II reaction centre complex and the light-harvesting complex. The ratio of light-harvesting complex to Photosystem II reaction centre complex is rather constant in all subchloroplast fractions suggesting a close association between these complexes. This was not so for the ratio of light-harvesting complex and the Photosystem I reaction centre complex. The lateral heterogeneity in the distribution of the photosystems between appressed and non-appressed membranes must have a profound impact on current understanding of both the distribution of excitation energy and photosynthetic electron transport between the photosystems.
研究了主要叶绿素 - 蛋白质复合物在垛叠和非垛叠类囊体膜之间的横向分布。通过SDS - 聚丙烯酰胺凝胶电泳方法解析了光系统I和II的反应中心复合物以及捕光复合物，该方法能使大部分叶绿素保持与蛋白质结合的状态。这些分析应用于显示来自不同类囊体区域的亚叶绿体组分。通过压榨处理或洋地黄皂苷破坏叶绿体后离心，将基质类囊体与基粒堆叠分开。通过水相聚合物双相分配法分离出源自基粒间隔的囊泡。在垛叠的基粒间隔区域，光系统I叶绿素 - 蛋白质复合物的量大幅减少，而光系统II反应中心复合物和捕光复合物则富集。与通过压榨或洋地黄皂苷处理得到的基粒堆叠组分相比，该组分中的高富集表明基粒光系统I主要局限于非垛叠的基粒端膜和边缘，并且基粒间隔主要含有光系统II反应中心复合物和捕光复合物。相比之下，基质类囊体中光系统I反应中心复合物高度富集。它们还含有约10 - 20%的总光系统II反应中心复合物和捕光复合物。在所有亚叶绿体组分中，捕光复合物与光系统II反应中心复合物的比例相当恒定，表明这些复合物之间存在紧密关联。光系统I反应中心复合物与捕光复合物的比例则并非如此。垛叠和非垛叠膜之间光系统分布的横向异质性必然会对当前关于光系统之间激发能分布和光合电子传递的理解产生深远影响。
