Use of attenuated total reflectance Fourier transform infrared spectroscopy to study lactosylceramide and GD3 DMPC bilayers

Attenuated total reflection Fourier transform infrared spectroscopy was used to monitor the formation of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), DMPC: lactosylceramide, and DMPC: GD3 lipid bilayers onto a zinc selenide surface. Infrared absorption peak position, bandwidth, and intensity were all used to monitor the formation, acyl chain ordering, and chemical environment within each bilayer. The results from this study indicate that the addition of glycosphingolipids into a DMPC lipid bilayer introduces decreases in both, acyl chain ordering, and homogeneity within the bilayer. GD3:DMPC lipid bilayers possess lipid chain characteristics that are indiscernible from those present in the lactosylceramide:DMPC bilayer, while possessing different structural head groups, indicating that the head group has little influence on the underlying lipid structure. Differences in the phosphate hydration are, however, evident between the three types of bilayer, with phosphate hydration decreasing in the order LacCer:DMPC (1223.4 cm−1) > DMPC only (1226 cm−1) > GD3:DMPC (1229.6 cm−1).