Barotropic phase transition between the lamellar liquid crystal phase and the inverted hexagonal phase of dioleoylphosphatidylethanolamine

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• 作者：Ryosuke Sueyoshi ; Kaori Tada ; Masaki Goto ; Nobutake Tamai ; Hitoshi Matsuki and Shoji Kaneshina
• 关键词：Inverted hexagonal phase ; Lamellar liquid crystal phase ; Phospholipid ; Phase transition ; Pressure
• 刊名：Colloids and Surfaces B: Biointerfaces
• 出版年：2006
• 出版时间：1 June 2006
• 年：2006
• 卷：50
• 期：1
• 页码：85-88
• 全文大小：168 K

文摘

The phase transition between the lamellar liquid crystal (L_α) phase and the inverted hexagonal (H_II) phase of dioleoylphosphatidylethanolamine (DOPE) in aqueous NaCl solutions was observed by means of differential scanning calorimetry (DSC) under ambient pressure and light-transmittance technique under high pressure. The pressure dependence of the transition temperature (dT/dp) and the thermodynamic quantities for the L_α/H_II transition were compared with those of another phase transition found in the DOPE bilayer membrane, which is the transition from the lamellar crystal (L_c) phase to the L_α phase. The dT/dp value of the L_α/H_II transition was about 3.5 times as large as that of the L_c/L_α transition while the thermodynamic quantities were significantly smaller than those of the latter to the contrary. Comparing the enthalpy and volume behavior of the L_α/H_II transition with that of the L_c/L_α transition, we concluded that the L_α/H_II transition can be regarded as the volume-controlled transition for the reconstruction of molecular packing.