The inverse hexagonal – inverse ribbon – lamellar gel phase transition sequence in low hydration DOPC:DOPE phospholipid mixtures

• Published in: Chemistry and physics of lipids Vol. 157; no. 1; pp. 56 - 60
• Main Authors: Kent, Ben, Garvey, Christopher J., Cookson, David, Bryant, Gary
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.01.2009; Elsevier
• Subjects: CALORIMETRY; Complex Mixtures - chemistry; Gels; HYDRATION; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; MEMBRANES; MIXTURES; Model membranes; Phase Transition; Phase transitions; Phosphatidylcholines - chemistry; Phosphatidylethanolamines - chemistry; Phospholipid; PHOSPHOLIPIDS; Ribbon phase; SCATTERING; Scattering, Small Angle; Small angle X-ray scattering; Synchrotrons; Temperature; Water - chemistry; X-Ray Diffraction; Model membranes; Phospholipid; 87.15.Zg; Ribbon phase; Phase transitions; Small angle X-ray scattering; 87.14.Cc
• ISSN: 0009-3084; 1873-2941
• DOI: 10.1016/j.chemphyslip.2008.10.003

The inverse hexagonal to inverse ribbon phase transition in a mixed phosphatidylcholine–phosphatidylethanolamine system at low hydration is studied using small and wide angle X-ray scattering. It is found that the structural parameters of the inverse hexagonal phase are independent of temperature. By contrast the length of each ribbon of the inverse ribbon phase increases continuously with decreasing temperature over a range of 50 ° C. At low temperatures the inverse ribbon phase is observed to have a transition to a gel lamellar phase, with no intermediate fluid lamellar phase. This phase transition is confirmed by differential scanning calorimetry.