Experimental Physics IV and Bayreuth Institute for Macromolecular Research (BIMF), University of Bayreuth, 95440 Bayreuth, Germany.
J Phys Chem B. 2013 Mar 21;117(11):3120-6. doi: 10.1021/jp4005218. Epub 2013 Mar 12.
We have revisited the RC-LH1 complex from Rhodopseudomonas (Rps.) acidophila for single-molecule spectroscopy. For the current study the pigment-protein complexes were stabilized in the detergent buffer solution using a relatively mild detergent (dodecyl-β-D-maltoside (DDM) instead of lauryldimethylamine N-oxide (LDAO)). This leads to a significant reduction of the fraction of broken/dissociated RC-LH1 complexes with respect to previous studies and has allowed us to investigate a sufficiently large sample of individual RC-LH1 complexes. For most of the complexes the fluorescence-excitation spectra exhibit a narrow spectral feature at the red end of the spectrum. Analysis of the statistics of the spectral properties yields a close resemblance with the results obtained on RC-LH1 complexes from Rps. palustris for which a low-resolution X-ray structure is available. Based on this comparison we come to the conclusion that for both species the RC-LH1 complex can be described by the same structural model, that is, an overall elliptical assembly of pigments that features a gap.
我们重新研究了嗜酸红假单胞菌（Rhodopseudomonas acidophila）的 RC-LH1 复合物，用于单分子光谱学研究。在当前的研究中，我们使用相对温和的去污剂（十二烷基-β-D-麦芽糖苷（DDM）代替了月桂基二甲基氧化胺（LDAO））在去污剂缓冲溶液中稳定色素蛋白复合物。与之前的研究相比，这导致 RC-LH1 复合物断裂/解离的比例显著降低，使我们能够研究足够数量的单个 RC-LH1 复合物。对于大多数复合物，荧光激发光谱在光谱的红色末端显示出一个狭窄的光谱特征。对光谱性质的统计分析结果与已报道的沼泽红假单胞菌（Rps. palustris）RC-LH1 复合物的结果非常相似，后者具有低分辨率的 X 射线结构。基于这一比较，我们得出结论，对于这两个物种，RC-LH1 复合物可以用相同的结构模型来描述，即一个具有间隙的整体椭圆形色素组装体。
