Structure of Functional Staphylococcus aureus α-Hemolysin Channels in Tethered Bilayer Lipid Membranes
Structure of Functional Staphylococcus aureus α-Hemolysin Channels in Tethered Bilayer Lipid Membranes
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DOI：
10.1016/j.bpj.2008.11.020
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发表时间：
2009-02-18
影响因子：
3.4
通讯作者：
Kasianowicz, John J.
中科院分区：
文献类型：
--
作者：
McGillivray, Duncan J.;Valincius, Gintaras;Kasianowicz, John J.
我们展示了一种方法，同时结构和功能的测定膜蛋白的整体。电阻抗谱表明，金黄色葡萄球菌α-溶血素通道的膜拴到金具有相同的性质，形成的独立的双层脂质膜。中子反射仪提供了通道和无序膜之间相互作用的高分辨率结构信息，验证了基于通道的X射线晶体结构的预测。膜的坚固性使得蛋白质能够在1.1埃内精确定位。通道的膜外帽结构域影响脂质头基区域和外膜小叶中的烷基链，并使头基显著脱水。结果表明，该技术可用于阐明其他蛋白质与膜的关联的分子细节，并可提供结构域组织和膜模拟物中跨膜蛋白的刺激响应重组的结构信息。
We demonstrate a method for simultaneous structure and function determination of integral membrane proteins. Electrical impedance spectroscopy shows that Staphylococcus aureus a-hemolysin channels in membranes tethered to gold have the same properties as those formed in free-standing bilayer lipid membranes. Neutron reflectometry provides high-resolution structural information on the interaction between the channel and the disordered membrane, validating predictions based on the channel's x-ray crystal structure. The robust nature of the membrane enabled the precise localization of the protein within 1.1 angstrom. The channel's extramembranous cap domain affects the lipid headgroup region and the alkyl chains in the outer membrane leaflet and significantly dehydrates the headgroups. The results suggest that this technique could be used to elucidate molecular details of the association of other proteins with membranes and may provide structural information on domain organization and stimuli-responsive reorganization for transmembrane proteins in membrane mimics.