Lateral diffusion coefficients of phospholipids in spherical bilayers on a solid support measured by 2H-nuclear-magnetic-resonance relaxation.

摘要: An alternative nuclear-magnetic-resonance (NMR) method for the measurement of lateral diffusion coefficient D phospholipids along plane a spherical bilayer on solid support is presented. values are determined at various temperatures palmitoyl-oleoyl-phosphatidylcholine (POPC) silica 640 nm diameter. The based upon quadrupolar transverse relaxation times obtained by Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence series different spacing times. It takes advantage fact that CPMG can progressively filter out contributions to arising from motions like diffusion, which slow NMR time scale. combination this with new membrane model system, single bilayers well-defined diameter, enables determination D. we obtain POPC supported [D=(2.1\ifmmode\pm\else\textpm\fi{}0.7)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}12}$ ${\mathrm{m}}^{2}$/s 10 \ifmmode^\circ\else\textdegree\fi{}C, D=(4.0\ifmmode\pm\else\textpm\fi{}0.8)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}12}$ 30 and D=(7.0\ifmmode\pm\else\textpm\fi{}1.0)\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}12}$ 50 \ifmmode^\circ\else\textdegree\fi{}C] in good agreement those other methods fluorescence recovery after photobleaching (FRAP) pulsed-field-gradient (PFG-NMR).