隨著蛋白結(jié)構(gòu)生物學(xué)的發(fā)展,，很多膜蛋白的X-射線晶體結(jié)構(gòu)已被確定，但關(guān)于處在它們原始膜環(huán)境中的蛋白的直接結(jié)構(gòu)信息卻很少,。
現(xiàn)在,，Swartz博士帶領(lǐng)的研究小組將中子衍射,、固體NMR光譜和分子動態(tài)模擬結(jié)合起來研究原始環(huán)境中的膜蛋白結(jié)構(gòu),，為包含S1-S4電壓感應(yīng)域（它們被膜蛋白用來感應(yīng)膜電壓變化并對其做出反應(yīng)）的類脂雙層膜的結(jié)構(gòu)和水合提供了一幅詳細的畫面。
研究結(jié)果表明,，這些電壓傳感器采用跨膜取向,，使周圍的類脂雙層發(fā)生小幅度變形，但變形幅度之大足以讓水分子能夠與膜發(fā)生相互作用,，從而使帶電殘體發(fā)生水合,，使跨膜電場成形，同時將能量和結(jié)構(gòu)擾動保持到最小程度,。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature08542
Structure and hydration of membranes embedded with voltage-sensing domains
Dmitriy Krepkiy 1 8, Mihaela Mihailescu 2 5 8, J. Alfredo Freites 2 3, Eric V. Schow 4, David L. Worcester 2 5 6, Klaus Gawrisch 7, Douglas J. Tobias 3, Stephen H. White 2 5 & Kenton J. Swartz1
Despite the growing number of atomic-resolution membrane protein structures, direct structural information about proteins in their native membrane environment is scarce. This problem is particularly relevant in the case of the highly charged S1–S4 voltage-sensing domains responsible for nerve impulses, where interactions with the lipid bilayer are critical for the function of voltage-activated ion channels. Here we use neutron diffraction, solid-state nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics simulations to investigate the structure and hydration of bilayer membranes containing S1–S4 voltage-sensing domains. Our results show that voltage sensors adopt transmembrane orientations and cause a modest reshaping of the surrounding lipid bilayer, and that water molecules intimately interact with the protein within the membrane. These structural findings indicate that voltage sensors have evolved to interact with the lipid membrane while keeping energetic and structural perturbations to a minimum, and that water penetrates the membrane, to hydrate charged residues and shape the transmembrane electric field.
1 Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
2 Department of Physiology and Biophysics, and Center for Biomembrane Systems,
3 Department of Chemistry and Institute for Surface and Interface Science,
4 Department of Physics and Astronomy and Institute for Genomics and Bioinformatics, University of California, Irvine, California 92697, USA
5 NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
6 Biology Division, University of Missouri, Columbia, Missouri 65211, USA
7 Laboratory of Membrane Biochemistry and Biophysics, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland 20892, USA
8 These authors contributed equally to this work.
