Mechanical properties and membrane tension of free-standing black lipid membranes

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K19091
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 34:Inorganic/coordination chemistry, analytical chemistry, and related fields
• Research Institution: Chiba University
• Principal Investigator: Fujinami Masanori 千葉大学, 大学院工学研究院, 教授 (50311436)
• Project Period (FY): 2018-06-29 – 2020-03-31
• Keywords: 生体膜 / 膜張力 / 人工脂質二分子膜 / 膜流動 / コレステロール / 光圧

Outline of Final Research Achievements

In this study, non-invasive measurement techniques of membrane tension and diffusion coefficients based on laser-induced surface deformation (LISD) spectroscopy and fluorescence recovery after photobleaching (FRAP) method are developed for studying self-standing bilayer lipid membranes (BLMs). In the cases of sterol effect in BLMs, increasing concentration of sterols in BLMs was found to increase membrane tension and decrease diffusion coefficients. Structural effects of sterols were also observed. I the cases of anion effects around BLMs, hydrophobic anion was found to decrease fluidity and increase membrane tensions. These results are important not only for composition/environmental properties of model cell membranes, it is a step to non-invasive mechanical property investigations of functioning cell membranes.

Free Research Field

分析化学

Academic Significance and Societal Importance of the Research Achievements

本研究では光圧を用いた非侵襲型界面張力測定法であるLISD法を膜張力測定に応用し，拡散係数測定法であるFRAP法と併せることで，従来法で必要だった接触や変形を伴うことなく脂質二分子膜の力学特性・分子間相互作用に対する組成・イオン種の影響評価が可能であることを示すことができた。これは組成・環境制御されたモデル生体膜における力学特性・分子間相互作用評価として重要であるだけでなく、今後より複雑な生体膜の機能と力学特性の関係評価においても本手法を応用できる可能性を示すものとして重要である。