Publication date: Available online 13 October 2014 Source:Journal of Magnetic Resonance
Author(s): Jesse E. McCaffrey , Zachary M. James , David D. Thomas
We have optimized the magnetic alignment of phospholipid bilayered micelles (bicelles) for EPR spectroscopy, by varying lipid composition and temperature. Bicelles have been extensively used in NMR spectroscopy for several decades, in order to obtain aligned samples in a near-native membrane environment and take advantage of the intrinsic sensitivity of magnetic resonance to molecular orientation. Recently, bicelles have also seen increasing use in EPR, which offers superior sensitivity and orientational resolution. However, the low magnetic field strength (less than 1 T) of most conventional EPR spectrometers results in homogeneously oriented bicelles only at a temperature well above physiological. To optimize bicelle composition for magnetic alignment at reduced temperature, we prepared bicelles containing varying ratios of saturated (DMPC) and unsaturated (POPC) phospholipids, using EPR spectra of a spin-labeled fatty acid to assess alignment as a function of lipid composition and temperature. Spectral analysis showed that bicelles containing an equimolar mixture of DMPC and POPC homogeneously align at 298 K, 20 K lower than conventional DMPC-only bicelles. It is now be possible to perform EPR studies of membrane protein structure and dynamics in well-aligned bicelles at physiological temperatures and below. Graphical abstract
DNP-enhanced NMR on aligned Lipid Bilayers at ambient Temperature
From The DNP-NMR Blog:
DNP-enhanced NMR on aligned Lipid Bilayers at ambient Temperature
Jakdetchai, O., et al., DNP-enhanced NMR on aligned Lipid Bilayers at ambient Temperature. J Am Chem Soc, 2014.
http://www.ncbi.nlm.nih.gov/pubmed/25333422
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10-24-2014 07:18 PM
[NMR paper] DNP-enhanced NMR on aligned Lipid Bilayers at ambient Temperature.
DNP-enhanced NMR on aligned Lipid Bilayers at ambient Temperature.
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J Am Chem Soc. 2014 Oct 21;
Authors: Jakdetchai O, Denysenkov V, Becker-Baldus J, Dutagaci B, Prisner T, Glaubitz C
Abstract
DNP-enhanced solid-state NMR has been shown to hold great potential for functional studies of membrane proteins at low temperatures due to its great sensitivity improvement. There are however numerous applications, for which experiments at ambient temperature...
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10-22-2014 12:34 PM
Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature
From The DNP-NMR Blog:
Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature
Solid-state DNP-NMR are typically performed at cryogenic temperatures and samples, especially bio-macromolecules often require cryo-protection. This is a recent review about sample preparation and cryo-protecting samples to preserve the spectral resolution.
Lee, M. and M. Hong, Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature. J Biomol NMR, 2014....
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08-27-2014 02:29 PM
[NMR paper] Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature.
Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature.
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J Biomol NMR. 2014 Jul 12;
Authors: Lee M, Hong M
Abstract
Solid-state NMR spectra of membrane proteins often show significant line broadening at cryogenic temperatures. Here we investigate the effects of several cryoprotectants to preserve the...
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07-13-2014 06:48 PM
Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature
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Abstract
Solid-state NMR spectra of membrane proteins often show significant line broadening at cryogenic temperatures. Here we investigate the effects of several cryoprotectants to preserve the spectral resolution of lipid membranes and membrane peptides at temperatures down to ~200Â*K. Trehalose, glycerol, dimethylsulfoxide (DMSO), dimethylformamide (DMF), and polyethylene glycol (PEG), were chosen. These compounds are...
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This article reviews the application of solid-state (2)H nuclear magnetic resonance (NMR) spectroscopy for investigating the deformation of lipid bilayers at the atomistic level. For...
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Aliphatic chain length by isotropic mixing (ALCHIM): determining composition of complex lipid samples by 1H NMR spectroscopy
Aliphatic chain length by isotropic mixing (ALCHIM): determining composition of complex lipid samples by 1H NMR spectroscopy
Abstract
Quantifying the amounts and types of lipids present in mixtures is important in fields as diverse as medicine, food science, and biochemistry. Nuclear magnetic resonance (NMR) spectroscopy can quantify the total amounts of saturated and unsaturated fatty acids in mixtures, but identifying the length of saturated fatty acid or the position of unsaturation by NMR is a daunting challenge. We have developed an NMR...
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Chemistry. 2014 Mar 13;
Authors: Schmidt P, Thomas L, Müller P, Scheidt HA, Huster D
Abstract
Optimization of Bicelle Lipid Composition and Temperature for EPR Spectroscopy of Aligned Membranes
Linear Mode
