Solid-state NMR paramagnetic relaxation enhancement immersion depth studies in phospholipid bilayers
KAUST DepartmentImaging and Characterization Core Lab
Advanced Nanofabrication, Imaging and Characterization Core Lab
Embargo End Date2011-08-25
Permanent link to this recordhttp://hdl.handle.net/10754/561548
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AbstractA new approach for determining the membrane immersion depth of a spin-labeled probe has been developed using paramagnetic relaxation enhancement (PRE) in solid-state NMR spectroscopy. A DOXYL spin label was placed at different sites of 1-palmitoyl-2-stearoyl-sn-glycero-3-phosphocholine (PSPC) phospholipid bilayers as paramagnetic moieties and the resulting enhancements of the longitudinal relaxation (T1) times of 31P nuclei on the surface of the bilayers were measured by a standard inversion recovery pulse sequence. The 31P NMR spin-lattice relaxation times decrease steadily as the DOXYL spin label moves closer to the surface as well as the concentration of the spin-labeled lipids increase. The enhanced relaxation vs. the position and concentration of spin-labels indicate that PRE induced by the DOXYL spin label are significant to determine longer distances over the whole range of the membrane depths. When these data were combined with estimated correlation times τc, the r-6-weighted, time-averaged distances between the spin-labels and the 31P nuclei on the membrane surface were estimated. The application of using this solid-state NMR PRE approach coupled with site-directed spin labeling (SDSL) may be a powerful method for measuring membrane protein immersion depth. © 2010 Elsevier Inc. All rights reserved.
CitationChu, S., Maltsev, S., Emwas, A.-H., & Lorigan, G. A. (2010). Solid-state NMR paramagnetic relaxation enhancement immersion depth studies in phospholipid bilayers. Journal of Magnetic Resonance, 207(1), 89–94. doi:10.1016/j.jmr.2010.08.012
SponsorsThis work was partially supported by the NIH Grant GM080542. The Bruker 500 MHz wide bore NMR spectrometer was obtained from the NSF Grant 10116333.
JournalJournal of Magnetic Resonance
PubMed Central IDPMC2978330