Palmitoyl oleoyl phosphatidylcholine

Example 54

Lipid bilayer studies were performed as described elsewhere (Sunstrom, 1996; Miller, 1986). A lipid mixture of palmitoyl-oleoyl-phosphatidylethanolamine, palmitoyl-oleoyl-phosphatidylserine and palmitoyl-oleoyl-phosphatidylcholine (5:3:2) (Avanti Polar Lipids, Alabaster, Ala.) was used. The lipid mixture was painted onto an aperture of 150-200 μm in the wall of a 1 ml delrin cup. The aperture separates two chambers, cis and trans, both containing salt solutions at different concentrations. The cis chamber was connected to ground and the trans chamber to the input of an Axopatch 200 amplifier. Normally the cis chamber contained 500 mM KCl and the trans 50 mM KCl. The bilayer formation was monitored electrically by the amplitude of the current pulse generated by a current ramp. The potentials were measured in the trans chamber with respect to the cis. The protein was added to the cis chamber and stirred until channel activity was seen. The currents were filtered at 1000 Hz, digitized at 5000 Hz and stored on magnetic disk.

The dengue virus M protein C-terminal peptide (DMVC) was dissolved in 2,2,2-trifluoroethanol (TFE) at 0.05 mg/ml to 1 mg/ml. 10 μl of this was added to the cis chamber of the bilayer which was stirred. Channel activity was seen within 15-30 min.