Lipid−Protein Interactions and Effect of Local Anesthetics in Acetylcholine Receptor-Rich Membranes from Torpedo marmorata Electric Organ
The selectivity of lipid−protein interaction for spin-labeled phospholipids and gangliosides in nicotinic acetylcholine receptor-rich membranes from Torpedo marmorata has been studied by ESR spectroscopy. The association constants of the spin-labeled lipids (relative to phosphatidylcholine) at pH 8....
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Published in | Biochemistry (Easton) Vol. 42; no. 30; pp. 9167 - 9175 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Chemical Society
05.08.2003
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Subjects | |
Online Access | Get full text |
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Summary: | The selectivity of lipid−protein interaction for spin-labeled phospholipids and gangliosides in nicotinic acetylcholine receptor-rich membranes from Torpedo marmorata has been studied by ESR spectroscopy. The association constants of the spin-labeled lipids (relative to phosphatidylcholine) at pH 8.0 are in the order cardiolipin (5.1) ≈ stearic acid (4.9) ≈ phosphatidylinositol (4.7) > phosphatidylserine (2.7) > phosphatidylglycerol (1.7) > GD1b ≈ GM1 ≈ GM2 ≈ GM3 ≈ phosphatidylcholine (1.0) > phosphatidylethanolamine (0.5). No selectivity for mono- or disialogangliosides is found over that for phosphatidylcholine. Aminated local anesthetics were found to compete with spin-labeled phosphatidylinositol, but to a much lesser extent with spin-labeled stearic acid, for sites on the intramembranous surface of the protein. The relative association constant of phosphatidylinositol was reduced in the presence of the different local anesthetics to the following extents: tetracaine (55%) > procaine (35%) ≈ benzocaine (30%). For stearic acid, only tetracaine gave an appreciable reduction (30%) in association constant. These displacements represent an intrinsic difference in affinity of the local anesthetics for the lipid−protein interface because the membrane partition coefficients are in the order benzocaine ≫ tetracaine ≈ procaine. |
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Bibliography: | istex:BD3CE79AEFF67E8E37E51AC1DD73BB69451AFFAF This work was supported by grants from the Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Argentina, and the Volkswagen Stiftung, FRG. H.R.A. was supported by a Deutscher Akademischer Austauschdienst e.V. (DAAD) fellowship. ark:/67375/TPS-VG3M15M2-J ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0006-2960 1520-4995 |
DOI: | 10.1021/bi034485q |