Abstract
The conversion of either the gel or the liquid crystal phase to the most stable subgel phase in dimyristoylphosphatidylethanolamine (DMPE)-water system at a water content of 25 mass% was studied by differential scanning calorimetry and isothermal calorimetry. The calorimetric experiments were performed for two samples depending on whether the thermal treatment of cooling to -60°C was adopted or not. In DSC of varying heating rate, exothermic peaks due to the partial conversion were observed at either temperatures just below the gel-to-liquid crystal phase transition at 50°C or temperatures where the liquid crystal phase is present as a metastable state. The enthalpies of conversion for both the gel and the liquid crystal phase were measured directly by the isothermal calorimetries at 47 and 53°C, respectively, where the exothermic peaks were observed by DSC and were compared with the enthalpy difference between the gel and subgel phases and that between the liquid crystal and subgel phases.
Similar content being viewed by others
References
M. Kodama, H. Hashigami and S. Seki, Thermochim. Acta, 88 (1985) 217.
M. Kodama, Thermochim. Acta, 109 (1986) 81.
M. Kodama, H. Hashigami and S. Seki, J. Colloid Interface Sci., 117 (1987) 497.
M. Kodama, H. Inoue and Y. Tsuchida, Thermochim. Acta, 266 (1995) 373.
H. Aoki and M. Kodama, J. Thermal Anal., 49 (1997) 839.
M. Kodama, T. Miyata and T. Yokoyama, Biochim. Biophys. Acta, 1168 (1993) 243.
M. Kodama, H. Aoki and T. Miyata, Biophys. Chem., 79 (1999) 205.
M. Kodama and H. Aoki, Recent Res. Dev. Biophys. Chem., 1 (2000) 27.
M. Kodama, H. Kato and H. Aoki, Thermochim. Acta., 352-353 (2000) 213.
M. Kodama and H. Aoki, in ‘Thermal Behavior of Dispersed Systems’, N. Garti, Ed., Marcel Dekker Inc., New York 2000, p. 247.
H. Chang and R. M. Epand, Biochim. Biophys. Acta, 728 (1983) 319.
S. Mulukutla and G. G. Shipley, Biochemistry, 23 (1984) 2514.
D. A. Wilkinson and J. F. Nagle, Biochemistry, 23 (1984) 1538.
M. Kodama, H. Aoki, H. Takahashi and I. H atta, Biochim. Biophys. Acta, 1329 (1997) 61.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Aoki, H., Koto, T. & Kodama, M. Calorimetric Investigation of Conversion to The Most Stable Subgel Phase of Phosphatidylethanolamine-water System. Journal of Thermal Analysis and Calorimetry 64, 299–306 (2001). https://doi.org/10.1023/A:1011517919999
Issue Date:
DOI: https://doi.org/10.1023/A:1011517919999