Thermal Stabilization of DMPC/DHPC Bicelles by Addition of Cholesterol Sulfate

Doping DMPC/DHPC bicelles with cholesterol sulfate broadens the temperature range over which stable alignment occurs, forming an aligned phase at lower temperatures even with high lipid concentrations. Cholesterol sulfate appears to combine the advantages of cholesterol with those of charged amphiphiles, stabilizing the aligned phase and preventing precipitation. This allows NMR data for RDC and CSA protein structure constraints to be acquired at or below room temperature, an obvious advantage for solid-state and solution studies of heat-sensitive proteins.