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NMR structural studies of membrane proteins in bilayer environments
Author(s) -
Radoicic Jasmina,
Park Sang Ho,
Opella Stanley J.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.792.36
Subject(s) - model lipid bilayer , membrane protein , chemistry , transmembrane protein , lipid bilayer , micelle , integral membrane protein , crystallography , bilayer , transmembrane domain , elasticity of cell membranes , peripheral membrane protein , membrane , biophysics , random hexamer , nuclear magnetic resonance spectroscopy , protein structure , lipid bilayer phase behavior , biochemistry , stereochemistry , biology , organic chemistry , receptor , aqueous solution
Membrane protein research focused on studying the structure, function, and interactions of proteins in membrane environments by NMR spectroscopy will be presented. Sample preparation is challenging because membrane proteins are generally low expressing in heterologous systems, hydrophobic, and difficult to re‐fold into their active conformations – any variation from the native structure results in inactive and/or mis‐folded protein. Typically, the purification or extraction of these proteins requires the use of detergents, which can be detrimental to their structure and function. Therefore, an important goal is the development and implementation of detergent‐free environments for NMR studies of membrane proteins. The main membrane environments used for NMR studies include micelles, bicelles, liposomes, and nano‐ and macro‐discs. Studying the same protein in different environments can reveal significant differences in the structure, conformation, and orientation of the protein. For example, the HIV‐1 protein Vpu, studied using static oriented sample solid state NMR, in different lipid bicelle environments resulted in different tilt angles of the protein in the model membrane as well as the absence (or presence) of a kink in the transmembrane helix, depending on the bilayer‐forming phospholipids. Another example is the structure obtained for the hepatitis C protein p7. In DPC micelles, the protein is a hexamer whereas in DHPC micelles the protein is a monomer, having the typical two‐transmembrane spanning protein topology. A macrodisc is a detergent‐free model membrane system composed of phospholipid bilayers surrounded by a peptide, protein, or styrene‐maleic acid (SMA) polymer belt, with a diameter of > 30nm. They serve to immobilize and magnetically align embedded membrane proteins. Examples of proteins having between one and seven trans‐membrane helices will be described, including G‐protein coupled receptors (GPCRs). This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .