POPC TTC vesicles

Fig. 10. High-pressure ID H-NMR spectra of sonicated POPC—TTC vesicles (25 mol% TTC) at room temperature (T=22°C) and pD = 5.5 (after Ref 49).

Figure 10 shows the NMR spectrum of sonicated POPC-TTC vesicles at room temperature and selected pressures. Already the one-dimensional NMR spectra exhibit some interesting features. With increasing pressure, the signal intensity of the acyl-chain protons at 0.85 and 1.24 ppm decrease due to the pressure-induced rigidization of the acyl-chains, as it is also observed for pure phospholipid samples. At pressures above the fluid-gel main transition, which is detected at a pressure of about 1200 bar at 20 °C in pure POPC dispersions, the acyl-chain signals of pure lipid samples disappear completely, whereas in the spectra of the POPC-TTC system considerable signal intensities remain even up to pressures of 2800 bar. Furthermore, we observe for the... 

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