Changes in protein structure under the membrane voltage sensing domain
Changes in protein structure under the membrane voltage sensing domain
With the development of protein structural biology, the X-ray crystal structure of many membrane proteins has been determined, but there is little direct structural information about the proteins in their original membrane environment.
Now, the research team led by Dr. Swartz combines neutron diffraction, solid-state NMR spectroscopy and molecular dynamics simulation to study the membrane protein structure in the original environment, which contains S1-S4 voltage sensing domains (they are used by membrane proteins to sense membrane voltage changes and The structure and hydration of the lipid bilayer membrane in response to it provides a detailed picture.
The results show that these voltage sensors adopt a transmembrane orientation to deform the surrounding lipid bilayer slightly, but the deformation is large enough to allow water molecules to interact with the membrane, thereby hydrating the charged residues, causing The electric field of the membrane is shaped while keeping energy and structural disturbances to a minimum.
Bio Valley recommends the original source:
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 str uctural 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.
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