Small Angle X-ray Diffraction Study on DOPC plus DOPE Liposomes containing Long 1-Alkanols

The effect of 1-alkanols (abbreviation CnOH, n = 8-18 is the even number of alkyl carbons) on the transition from lamellar L-alpha to inverted hexagonal H-II phase of multilamellar dioleylphosphatidylcholine (DOPC) + dioleylphosphatidylethanolamine (DOPE) vesicles at full hydration was studied using small angle X-ray diffraction. For DOPC:DOPE = 1:9 molar ratio the phase transition temperature T-BH was observed at similar to 40 degrees C. The CnOHs studied caused a significant decrease of T-BH. The hexagonal phase was observed at presence of shorter alkanols (C8OH - C14OH), at 0.4:1 alkanol:lipid molar ratio, even at 5 degrees C. For C16OH and C18OH the offset of L-alpha > H-II transition was detected.