Crystallogenesis of Membrane Proteins Mediated by Polymer-Bounded Lipid Nanodiscs
Crystallogenesis of Membrane Proteins Mediated by Polymer-Bounded Lipid Nanodiscs
复制标题
DOI：
10.1016/j.str.2016.12.004
复制
发表时间：
2017-02-07
期刊：
影响因子：
5.7
通讯作者：
Ernst, Oliver P.
中科院分区：
文献类型：
--
作者：
Broecker, Jana;Eger, Bryan T.;Ernst, Oliver P.
对于一些膜蛋白，洗涤剂介导的增溶会损害蛋白质的稳定性和功能，通常会损害生物物理和结构分析。因此，膜蛋白结构的测定一直是蛋白质晶体学领域的瓶颈。在这里，作为传统洗涤剂介导的替代方法，我们报道了一种重组产生的膜蛋白的结晶形成，这种膜蛋白从未离开过脂质双分子层环境。我们使用苯乙烯-马来酸（SMA）共聚物将脂质包裹的蛋白质溶解到SMA纳米圆盘中，通过亲和层析和尺寸排除层析纯化这些圆盘，并将蛋白质转移到脂质立方相（LCP）中进行中介孔结晶。由此获得的a-螺旋七跨膜微生物紫红质的2.0埃结构是高质量的，与传统的基于洗涤剂的纯化和随后的LCP结晶获得的2.2埃结构几乎相同。
For some membrane proteins, detergent-mediated solubilization compromises protein stability and functionality, often impairing biophysical and structural analyses. Hence, membrane-protein structure determination is a continuing bottleneck in the field of protein crystallography. Here, as an alternative to approaches mediated by conventional detergents, we report the crystallogenesis of a recombinantly produced membrane protein that never left a lipid bilayer environment. We used styrene-maleic acid (SMA) copolymers to solubilize lipid-embedded proteins into SMA nanodiscs, purified these discs by affinity and size-exclusion chromatography, and transferred proteins into the lipidic cubic phase (LCP) for in meso crystallization. The 2.0-angstrom structure of an a-helical seven-transmembrane microbial rhodopsin thus obtained is of high quality and virtually identical to the 2.2-angstrom structure obtained from traditional detergent-based purification and subsequent LCP crystallization.