FIGURE 2.

¹H NMR spectra of magnetically aligned DMPC/DHPC (q = 4.5) bicelles incorporating various amounts of DMPE-PEG 2000 and acquired using a spin echo sequence with a delay of 10 ms. The lower spectrum was obtained with bicelles lacking DMPE-PEG 2000. The intense resonance at 4.2 ppm is assigned to water, whereas the small resonance at 3.2 ppm is assigned to the choline quaternary methyls of DHPC. Other proton resonances are not visible due to their short transverse relaxation times. The middle spectrum was obtained with bicelles containing 1 mol % DMPE-PEG 2000. In addition to the water resonance, the ethoxy protons of the PEG group are readily visible at 3.3 ppm, overlapping the resonance of the DHPC choline quaternary methyls. The upper spectrum was obtained with bicelles containing 2 mol % DMPE-PEG 2000. The correspondence between the amount of DMPE-PEG 2000 and intensity of the resonance at 3.3 ppm is evident.