2012年8月21日
Study on the subgel-phase formation using an asymmetric phospholipid bilayer membrane by high-pressure fluorometry
Langmuir
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- 巻
- 28
- 号
- 33
- 開始ページ
- 12191
- 終了ページ
- 12198
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1021/la3020173
The myristoylpalmitoylphosphatidylcholine (MPPC) bilayer membrane shows a complicated temperature-pressure phase diagram. The large portion of the lamellar gel (Lβ′), ripple gel (Pβ′) , and pressure-induced gel (LβI) phases exist as metastable phases due to the extremely stable subgel (Lc) phase. The stable Lc phase enables us to examine the properties of the Lc phase. The phases of the MPPC bilayers under atmospheric and high pressures were studied by small-angle neutron scattering (SANS) and fluorescence spectroscopy using a polarity-sensitive fluorescent probe Prodan. The SANS measurements clearly demonstrated the existence of the metastable LβI phase with the smallest lamellar repeat distance. From a second-derivative analysis of the fluorescence data, the line shape for the Lc phase under high pressure was characterized by a broad peak with a minimum of ca. 460 nm. The line shapes and the minimum intensity wavelength (λ″min) values changed with pressure, indicating that the Lc phase has highly pressure-sensible structure. The λ″min values of the Lc phase spectra were split into ca. 430 and 500 nm in the L βI phase region, which corresponds to the formation of a interdigitated subgel Lc (LcI) phase. Moreover, the phase transitions related to the Lc phase were reversible transitions under high pressure. Taking into account the fluorescence behavior of Prodan for the Lc phase, we concluded that the structure of the Lc phase is highly probably a staggered structure, which can transform into the L cI phase easily. © 2012 American Chemical Society.
- リンク情報
- ID情報
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- DOI : 10.1021/la3020173
- ISSN : 0743-7463
- ISSN : 1520-5827
- eISSN : 1520-5827
- PubMed ID : 22823885
- SCOPUS ID : 84865495527