Bilayer in Small Bicelles Revealed by Lipid−Protein Interactions Using NMR Spectroscopy Export

@article{citeulike:3343313, abstract = {Abstract: Intermolecular nuclear Overhauser effects (NOEs) between the integral outer membrane protein OmpX from Escherichia coli and small bicelles of dihexanoyl phosphatidylcholine (DHPC) and dimyristoyl phosphatidylcholine (DMPC) give insights into proteinlipid interactions. Intermolecular NOEs between hydrophobic tails of lipid and protein in the bicelles cover the surface area of OmpX forming a continuous cylindric jacket of approximately 2.7 nm in height. These NOEs originate only from DMPC molecules, and no NOEs from DHPC are observed. Further, these NOEs are mainly from methylene groups of the hydrophobic tails of DMPC, and only a handful of NOEs arise from methyl groups of the hydrophobic tails. The observed contacts indicate that the hydrophobic tails of DMPC are oriented parallel to the surface of OmpX and thus DMPC molecules form a bilayer in the vicinity of the protein. Thus, a bilayer exists in the small bicelles not only in the absence of but also in the presence of a membrane protein. In addition, the number of NOEs between the polar head groups of lipid molecules and protein is increased in the bicelles compared with those in micelles. This observation may be due to the closely packed head groups of the bilayer. Moreover, irregularity of hydrophobic interactions in the middle of the bilayer environment was observed. This observation together with the interactions between polar head groups and proteins gives a possible rationale for structural and functional differences of membrane proteins solubilized in micelles and in bilayer systems and hints at structural differences between protein-free and protein-loaded bilayers.}, address = {Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Gottingen, Germany, and Department of Chemistry, Texas A\&M University, College Station, Texas 77843}, author = {Lee, Donghan and Walter, Korvin F. and Bru\&\#x308;ckner, Ann-Kathrin and Hilty, Christian and Becker, Stefan and Griesinger, Christian}, citeulike-article-id = {3343313}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/ja803686p}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/ja803686p}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/18817394}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=18817394}, day = {26}, doi = {10.1021/ja803686p}, journal = {J. Am. Chem. Soc.}, keywords = {bicelles, imp, micelles, ompx}, month = {September}, posted-at = {2008-10-14 02:02:05}, priority = {2}, title = {Bilayer in Small Bicelles Revealed by Lipid\&\#x2212;Protein Interactions Using NMR Spectroscopy}, url = {http://dx.doi.org/10.1021/ja803686p}, year = {2008} }

TY - JOUR ID - citeulike:3343313 L3 - citeulike-article-id:3343313 N2 - Abstract: Intermolecular nuclear Overhauser effects (NOEs) between the integral outer membrane protein OmpX from Escherichia coli and small bicelles of dihexanoyl phosphatidylcholine (DHPC) and dimyristoyl phosphatidylcholine (DMPC) give insights into proteinlipid interactions. Intermolecular NOEs between hydrophobic tails of lipid and protein in the bicelles cover the surface area of OmpX forming a continuous cylindric jacket of approximately 2.7 nm in height. These NOEs originate only from DMPC molecules, and no NOEs from DHPC are observed. Further, these NOEs are mainly from methylene groups of the hydrophobic tails of DMPC, and only a handful of NOEs arise from methyl groups of the hydrophobic tails. The observed contacts indicate that the hydrophobic tails of DMPC are oriented parallel to the surface of OmpX and thus DMPC molecules form a bilayer in the vicinity of the protein. Thus, a bilayer exists in the small bicelles not only in the absence of but also in the presence of a membrane protein. In addition, the number of NOEs between the polar head groups of lipid molecules and protein is increased in the bicelles compared with those in micelles. This observation may be due to the closely packed head groups of the bilayer. Moreover, irregularity of hydrophobic interactions in the middle of the bilayer environment was observed. This observation together with the interactions between polar head groups and proteins gives a possible rationale for structural and functional differences of membrane proteins solubilized in micelles and in bilayer systems and hints at structural differences between protein-free and protein-loaded bilayers. JF - J. Am. Chem. Soc. AD - Department of NMR-Based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Gottingen, Germany, and Department of Chemistry, Texas A&M University, College Station, Texas 77843 TI - Bilayer in Small Bicelles Revealed by Lipid−Protein Interactions Using NMR Spectroscopy KW - bicelles KW - imp KW - micelles KW - ompx AU - Lee, Donghan AU - Walter, Korvin AU - Brückner, Ann-Kathrin AU - Hilty, Christian AU - Becker, Stefan AU - Griesinger, Christian PY - 2008/09/26/ UR - http://dx.doi.org/10.1021/ja803686p ER -