2007 Fiscal Year Final Research Report Summary
Hierarchical Structures and Phase Transitions of Lipid Membranes
| Project/Area Number |
17540382
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Biophysics/Chemical physics
|
|---|
| Research Institution | Kyoto University |
|---|
Principal Investigator |
SETO Hideki Kyoto University, Graduate School of Science, Associate Professor (60216546)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YOSHIKAWA Kenichi Kyoto University, Graduate School of Science, Professor (80110823)
KITAHATA Hiroyuki Kyoto University, Graduate School of Science, Assistant Professor (20378532)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Keywords | amphiphilic membrane / lipid membrane / giant vesicle / unbinding transition / small-angle x-ray scattering / anomalous swelling / neutron spin echo / bending modulus |
|---|
| Research Abstract |
Biomembrane is mainly comprised of phospholipid molecules. Due to the amphiphilic property of phospholipid, these molecules assemble into bilayers in water to form vesicles. To investigate a model cell system, it is important to establish a method for creating giant vesicles (GVs) with a diameter above 1 micro-meter, which are comparable in size to living cells.
A natural swelling method, in which GVs are spontaneously formed by hydrating multi-stacked phospholipid dry film on a solid substrate, would be quite useful for creating a model cell because no physical or chemical stresses are applied to GVs. In this method, each lipid bilayer should peel off nom the stack of bilayers on a substrate and form a vesicle. Thus, we investigated the hydration process of multi-stacked phospholipid bilayers to form GVs by time-resolved small-angle X-ray scattering. The result indicated that the hydration proceeds in three stages. In the early stage, water molecules penetrate between lipid bilayers, and in the intermediate stage the lipid bilayers swell and reach a quasi-stable state. In the late stage, lipid bilayers gradually peel off from the stack. The kinetics of the peeling-off is discussed in terms of Kramers' broiling Only the outermost bilayers is unbound due to thermal fluctuations, and giant uni-lamellar vesicles will be formed.
Next, we investigated membrane fluctuations of lipid membranes by means of neutron spin echo spectroscopy. The hardening of a lipid bilayer upon approaching the main transition point in the anomalous swelling regime was observed, which naturally connects the bending modulus in the gel phase belog the main transition temperature.
|
-
-
-
-
-
-
-
-
-
-
-
-
[Journal Article] Development of and π/2 flippers for a neutron spin echo spectrometer2007
Author(s)
T., Takeda, N.L., Yamada, K., Katou, M., Nagao, H., Seto, Y., Kawabata, M., Takeda, N., Torikai
-
Journal Title
Journal of Neutron Research 15
Pages: 83-89
Description
「研究成果報告書概要(欧文)」より
-
-
[Journal Article] Strucutural Changes of Dipalmitoyl Phosphatidylcholine Aqueous Solution Induced by Temperature, Pressure, and Adding Ethanol2007
Author(s)
H., Seto, M., Hishida, H., Nobutou, N.L., Yamada, M., Nagao, T., Takeda
-
Journal Title
Journal of Physical Society of Japan 76, 5
Pages: 054602-1-7
Description
「研究成果報告書概要(欧文)」より
-
-
-
-
-
-
-
-
-
-
-
-
-
[Journal Article] SAXS, SANS and NSE studies on the "unbound state" in the DPPC/water/CaCl2 system2005
Author(s)
N.L., Yamada, H., Seth, T., Takeda, M., Nagao, Y., Kawabata, K., Inoue
-
Journal Title
Journal of Physical Society of Japan 74
Pages: 2853-2859
Description
「研究成果報告書概要(欧文)」より
-
-
-
-
-
-
