The Interaction Of Dmso With Model Membranes. I. Comparison Of Dmso And D(6)-Dmso: A Dsc And Ir Investigation

The effect of deuterated solvents on the main phase transition (Tm) temperature of large unilamellar vesicles (LUVs) of 1,2-dipaimitoyl phosphatidylcholine (DPPC) was examined by infrared spectroscopy and differential scanning calorimetry. There was no significant difference in the Tm, DeltaH of the main transition, or cooperativity when water was replaced by deuterium oxide (D2O) in the preparation of the vesicles or when dimethylsulfoxide (DMSO) was replaced by hexadeutero-dimethylsulfoxide (d(6)-DMSO) in either D2O or water. These results provide the necessary advance for further structural, kinetic, and thermodynamic investigations of DMSO interactions with membranes and lipid vesicles.