pH and Potential Transients of the bc1 Complex Co-Reconstituted in Proteo-Lipobeads with the Reaction Center from Rb. sphaeroides

详细信息    查看全文

• 作者：Andreas F. Geiss ; Raghav Khandelwal ; Dieter Baurecht ; Christina Bliem ; Ciril Reiner-Rozman ; Michael Boersch ; G. Matthias Ullmann ; Leslie M. Loew ; Renate L. C. Naumann
• 刊名：Journal of Physical Chemistry B
• 出版年：2017
• 出版时间：January 12, 2017
• 年：2017
• 卷：121
• 期：1
• 页码：143-152
• 全文大小：647K
• ISSN：1520-5207

文摘

His-tag technology is employed to bind membrane proteins, such as the bc₁ complex and the reaction center (RC) from Rhodobacter sphaeroides, to spherical as well as planar surfaces in a strict orientation. Subsequently, the spherical and planar surfaces are subjected to in situ dialysis to form proteo-lipobeads (PLBs) and protein-tethered bilayer membranes, respectively. PLBs based on Ni-nitrileotriacetic acid-functionalized agarose beads that have diameters ranging from 50 to 150 μm are used to assess proton release and membrane potential parameters by confocal laser-scanning microscopy. The pH and potential transients are thus obtained from bc₁ activated by the RC. To assess the turnover of bc₁ excited by the RC in a similar setting, we used the planar surface of an attenuated total reflection crystal modified with a thin gold layer to carry out time-resolved surface-enhanced IR absorption spectroscopy triggered by flash lamp excitation. The experiments suggest that both proteins interact in a cyclic manner in both environments. The activity of the proteins seems to be preserved in the same manner as that in chromatophores or reconstituted in liposomes.