Cholesterol Suppresses Pressure-induced Interdigitation of Dipalmitoylphosphatidylcholine Bilayer Membrane
We investigated the effect of cholesterol on the pressure-induced interdigitation of dipalmitoylphosphatidylcholine (DPPC) bilayer membrane by fluorescence technique using 6-propionyl-2-(dimethylamino)naphthalene (Prodan) as a probe. The interdigitation pressure (IP), minimum pressure required for the bilayer interdigitation, was elevated with increasing cholesterol composition (<I>C</I><SUB>ch</SUB>) up to ca. 2 mol %. Further increase of <I>C</I><SUB>ch</SUB> did not give any effect on the IP value. Finally, the interdigitation could not be observed at <I>C</I><SUB>ch</SUB>=8 mol %. Constructed pressure–<I>C</I><SUB>ch</SUB> phase diagram at 50 °C suggests that the retardation and the abolition of the interdigitation are attributable to an interference effect and eventual formation of ordered molecular orientation induced by cholesterol.
- Chemistry letters
Chemistry letters 37(6), 604-605, 2008-06-05
The Chemical Society of Japan