Kynde Søren A R, Skar-Gislinge Nicholas, Pedersen Martin Cramer, Midtgaard Søren Roi, Simonsen Jens Baek, Schweins Ralf, Mortensen Kell, Arleth Lise
Structural Biophysics, Niels Bohr Institute, Faculty of Science, University of Copenhagen, Denmark.
Institute Laue-Langevin, Grenoble, France.
Acta Crystallogr D Biol Crystallogr. 2014 Feb;70(Pt 2):371-83. doi: 10.1107/S1399004713028344. Epub 2014 Jan 29.
Monomeric bacteriorhodopsin (bR) reconstituted into POPC/POPG-containing nanodiscs was investigated by combined small-angle neutron and X-ray scattering. A novel hybrid approach to small-angle scattering data analysis was developed. In combination, these provided direct structural insight into membrane-protein localization in the nanodisc and into the protein-lipid interactions. It was found that bR is laterally decentred in the plane of the disc and is slightly tilted in the phospholipid bilayer. The thickness of the bilayer is reduced in response to the incorporation of bR. The observed tilt of bR is in good accordance with previously performed theoretical predictions and computer simulations based on the bR crystal structure. The result is a significant and essential step on the way to developing a general small-angle scattering-based method for determining the low-resolution structures of membrane proteins in physiologically relevant environments.
通过小角中子散射和X射线散射相结合的方法，对重构于含POPC/POPG的纳米盘中的单体细菌视紫红质（bR）进行了研究。开发了一种用于小角散射数据分析的新型混合方法。这些方法相结合，提供了关于膜蛋白在纳米盘中的定位以及蛋白-脂质相互作用的直接结构见解。研究发现，bR在盘平面内横向偏心，并且在磷脂双层中略有倾斜。双层的厚度因bR的掺入而减小。观察到的bR倾斜与先前基于bR晶体结构进行的理论预测和计算机模拟结果高度一致。该结果是朝着开发一种基于小角散射的通用方法迈出的重要且关键的一步，该方法用于确定生理相关环境中膜蛋白的低分辨率结构。
