Electrochemical and PM-IRRAS a Glycolipid-Containing Biomimetic Membrane Prepared Using Langmuir-Blodgett/Langmuir-Schaefer Deposition

Differential capacitance, chronocoulometry, and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) measurements were used to characterize the structure and orientation of a DMPC + cholesterol + GM(1) (60:30:10 mol %) bilayer supported at a Au(111) electrode surface prepared using combined Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) deposition. The electrochemical measurements indicate that the incorporation of ganglioside GM(1) into the membrane significantly improves the quality of the bilayer, reflected in the very low capacitance value of similar to 0.8 mu F cm(-2). An analysis of the infrared data suggests that the incorporation of the glycolipid into the membrane changes both the orientation of the lipid acyl chains in the membrane and the hydration of the membrane, particularly with respect to the interfacial region of the lipids.