Effect of deuterium oxide on the thermodynamic quantities associated with phase transitions of phosphatidylcholine bilayer membranes
| Autor: | Shoji Kaneshina, Hiroko Okuno, Masataka Kusube, Hitoshi Matsuki, Fumihiko Sakano |
|---|---|
| Jazyk: | angličtina |
| Předmět: |
inorganic chemicals
Phase transition 1 2-Dipalmitoylphosphatidylcholine Lipid Bilayers Biophysics Analytical chemistry Biochemistry Phospholipid bilayer chemistry.chemical_compound Differential scanning calorimetry Phase (matter) Pressure Interdigitation Lipid bilayer phase behavior Lipid bilayer Phospholipids Calorimetry Differential Scanning Chemistry Bilayer Temperature Phospholipid Ethers Water Cell Biology Lipid bilayer mechanics Lipids Dipalmitoylphosphatidylcholine Deuterium oxide Phosphatidylcholines Thermodynamics lipids (amino acids peptides and proteins) |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. (1):92-100 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/j.bbamem.2005.03.005 |
| Popis: | The bilayer phase transitions of three kinds of phospholipids, dipalmitoylphosphatidylcholine (DPPC), distearoylphosphatidylcholine (DSPC) and dihexadecylphosphatidylcholine (DHPC), in deuterium oxide (D(2)O) and hydrogen oxide (H(2)O) were observed by differential scanning calorimetry (DSC) under ambient pressure and light-transmittance measurements under high pressure. The DSC measurements showed that the substitution of H(2)O by D(2)O affected the pretransition temperatures and the main-transition enthalpies of all PC bilayers. The temperature-pressure phase diagrams for these PC bilayer membranes in both solvents were constructed by use of the data of light-transmittance measurements. Regarding the main transition of all PC bilayer membranes, there was no appreciable difference between the transition temperatures in D(2)O and H(2)O under high pressure. On the other hand, the phase transitions among the gel phases including the pretransition were significantly affected by the solvent substitution. The thermodynamic quantities of phase transitions for the PC bilayer membranes were evaluated and the differences in thermodynamic properties by the water substitution were considered from the difference of interfacial-free energy per molecule in the bilayer in both solvents. It was proved that the substitution of H(2)O by D(2)O causes shrinkage of the molecular area of phospholipid at bilayer interface due to the difference in bond strength between deuterium and hydrogen bonds and produces the great influence on the bilayer phase with the smaller area. Further, the induction of bilayer interdigitation in D(2)O turned out to need higher pressures than in H(2)O. |
| Databáze: | OpenAIRE |
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