ID 111087
Author
Endo, Shigeru Tokushima University
Sueyoshi, Ryosuke Tokushima University
Keywords
Differential scanning calorimetry
Lipid bilayer membrane
Phase stability
Phase transition
Phosphatidylethanolamine
Pressure
Content Type
Journal Article
Description
The bilayer phase transitions of four diacylphosphatidylethanolamines (PEs) with matched saturated acyl chains (Cn = 12, 14, 16 and 18) and two PEs with matched unsaturated acyl chains containing a different kind of double bonds were observed by differential scanning calorimetry under atmospheric pressure and light-transmittance measurements under high pressure. The temperature-pressure phase diagrams for these PE bilayer membranes were constructed from the obtained phase-transition data. The saturated PE bilayer membranes underwent two different phase transitions related to the liquid crystalline (Lα) phase, the transition from the hydrated crystalline (Lc) phase and the chain melting (gel (Lβ) to Lα) transition, depending on the thermal history. Pressure altered the gel-phase stability of the bilayer membranes of PEs with longer chains at a low pressure. Comparing the thermodynamic quantities of the saturated PE bilayer membranes with those of diacylphosphatidylcholine (PC) bilayer membranes, the PE bilayer membranes showed higher phase-transition temperatures and formed more stable Lc phase, which originates from the strong interaction between polar head groups of PE molecules. On the other hand, the unsaturated PE bilayer membranes underwent the transition from the Lα phase to the inverted hexagonal (HII) phase at a high temperature and this transition showed a small transition enthalpy but high-pressure responsivity. It turned out that the kind of double bonds markedly affects both bilayer-bilayer and bilayer-nonbilayer transitions and the Lα/HII transition is a volume driven transition for the reconstruction of molecular packing. Further, the phase-transition behavior was explained by chemical potential curves of bilayer phases.
Journal Title
Biochimica et Biophysica Acta (BBA) - Biomembranes
ISSN
00052736
NCID
AA00564657
AA11522874
Publisher
Elsevier
Volume
1859
Issue
7
Start Page
1222
End Page
1232
Published Date
2017-03-31
Rights
© 2017 Elsevier B.V. All rights reserved. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Author
departments
Bioscience and Bioindustry
Science and Technology