High-resolution J-coupled 13C MAS NMR spectroscopy of lipid membranes.
We propose the use of Lee-Goldburg decoupling in high-resolution natural abundance 13C CP-MAS NMR spectroscopy to obtain J-resolved multiplets from membrane lipids, and the use of these in spectral assignment and to investigate changes in molecular and segmental dynamics within chemical shift-resolved lipid groups. Spectroscopic characteristics of hydrated DPPC bilayers are reported, including J1CH-couplings from the liquid crystalline and gel phases. The observed J1thetaCH values are scaled in the Lee-Goldburg experiment by a factor of approximately 3(-1/2) and corrected J1CH values on the order of 150 Hz compare well with indirect measurements. The J-resolved multiplets show J1thetaCH-couplings from the chain region to be approximately 20% lower than couplings determined from the headgroup, with backbone values falling between the two. Sensitivity of Lee-Goldburg decoupling to molecular motions reveals changes in hydrocarbon chain and backbone segmental dynamics across the main phospholipid transition and reduction in headgroup mobility below the pre-transition.
Ciesielski
Filip
F
School of Biomedical Sciences and Institute of Infection and Immunity, University of Nottingham, Nottingham NG7 2UH, UK.
Griffin
David C
DC
Rittig
Michael
M
Bonev
Boyan B
BB
D002152:Calorimetry, Differential Scanning; D002247:Carbon Isotopes / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008560:Membrane Fluidity / Q000502:physiology; D008563:Membrane Lipids / Q000737:chemistry*; D008565:Membrane Proteins / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010743:Phospholipids / Q000737:chemistry*; D013816:Thermodynamics; D014961:X-Ray Diffraction
D002247:Carbon Isotopes; D008051:Lipid Bilayers; D008563:Membrane Lipids; D008565:Membrane Proteins; D010743:Phospholipids