Cell-free Expressed Bacteriorhodopsin in Different Soluble Membrane Mimetics: Biophysical Properties and NMR Accessibility
Cell-free Expressed Bacteriorhodopsin in Different Soluble Membrane Mimetics: Biophysical Properties and NMR Accessibility
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DOI：
10.1016/j.str.2013.01.005
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发表时间：
2013-03-05
期刊：
影响因子：
5.7
通讯作者：
Wagner, Gerhard
中科院分区：
文献类型：
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作者：
Etzkorn, Manuel;Raschle, Thomas;Wagner, Gerhard
选择合适的膜模拟环境对膜蛋白的研究至关重要。非传统的表面活性剂，如两亲聚合物（amphipols）和脂质双层纳米盘，已被引入作为有前途的环境，可以克服固有的缺点的洗涤剂胶束系统。然而，对不同环境对包埋蛋白质的影响的结构见解是有限的。在这里，我们提出了一个比较研究的七螺旋膜蛋白细菌视紫红质在洗涤剂胶束，amphipols，和nanodisks。我们的研究结果证实，非传统的环境可以增加功能性细菌视紫红质的稳定性，并表明，折叠良好的七螺旋膜蛋白，在原则上，可通过溶液-NMR方法在两性分子和磷脂纳米盘。我们的数据区分区域的细菌视紫红质介导的膜/溶剂接触在测试环境中，而蛋白质的功能内核仍然几乎不受干扰。所提供的数据允许比较所研究的膜模拟物的NMR光谱质量和结构研究所需的热稳定性。
Selecting a suitable membrane-mimicking environment is of fundamental importance for the investigation of membrane proteins. Nonconventional surfactants, such as amphipathic polymers (amphipols) and lipid bilayer nanodiscs, have been introduced as promising environments that may overcome intrinsic disadvantages of detergent micelle systems. However, structural insights into the effects of different environments on the embedded protein are limited. Here, we present a comparative study of the heptahelical membrane protein bacteriorhodopsin in detergent micelles, amphipols, and nanodiscs. Our results confirm that nonconventional environments can increase stability of functional bacteriorhodopsin, and demonstrate that well-folded heptahelical membrane proteins are, in principle, accessible by solution-NMR methods in amphipols and phospholipid nanodiscs. Our data distinguish regions of bacteriorhodopsin that mediate membrane/solvent contacts in the tested environments, whereas the protein's functional inner core remains almost unperturbed. The presented data allow comparing the investigated membrane mimetics in terms of NMR spectral quality and thermal stability required for structural studies.