Kinetic effects in the differential scanning calorimetry cooling scans of phosphatidylethanolamines

• Published in: Chemistry and physics of lipids Vol. 49; no. 1; pp. 101 - 104
• Main Authors: Epand, Richard M., Epand, Raquel F.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.11.1988; Elsevier Science
• Subjects: Chemistry; Colloidal state and disperse state; differential scanning calorimetry; Exact sciences and technology; General and physical chemistry; hexagonal phase; Membranes; phase transition; phosphatidylethanolamine; Porous materials; phosphatidylethanolamine; phase transition; hexagonal phase; differential scanning calorimetry; Colloidal gel; Differential scanning calorimetry; Phosphatidylethanolamine; Temperature; Phospholipid; Kinetics; Bilayer; Liquid crystals; Saline solution; Phase transitions
• ISSN: 0009-3084; 1873-2941
• DOI: 10.1016/0009-3084(88)90070-9

We present the first high sensitivity differential scanning calorimetry (DSC) cooling scans of dielaidoylphosphatidylethanolamine (DEPE) and of 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE). The hexagonal to bilayer transitions observed on cooling are shifted to lower temperature than on heating. The temperature of these transitions in cooling, but not in heating, scans depends on the scan rate with lower transition temperaures being observed at more rapid scan rates. These results indicate that the hexagonal to bilayer phase transition rate is slow compared to the scan rates used. The liquid crystalline to gel transition of these phosphatidylethanolamines becomes more complex in cooling scans, exhibiting multiple peaks. This phenomenon may be a result of changes in the radius of curvature of the bilayer.