Artificial biomembrane reaction fields applying lipid bilayer membranes and solid-liquid-interface functions

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02690
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 32010:Fundamental physical chemistry-related
• Research Institution: Toyohashi University of Technology
• Principal Investigator: Tero Ryugo 豊橋技術科学大学, 工学(系)研究科(研究院), 教授 (40390679)
• Co-Investigator(Kenkyū-buntansha): 戸澤 譲 埼玉大学, 理工学研究科, 教授 (90363267)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 脂質二重膜 / イオンチャネル / 原子間力顕微鏡 / 無細胞合成

Outline of Final Research Achievements

Using an artificial lipid bilayer system and a cell-free protein synthesis system, we aimed to fabricate a functional molecular assembly comprising of membrane proteins a lipid bilayer and to clarify its working mechanism.
We used ternary lipid bilayers of phosphatidylethanolamine (PE), phosphatidylcholine (PC), and cholesterol (Chol), which have been used for the channel current measurement of various ion channels in previous studies A microdomain is formed in this PE+PC+Chol-bilayer and it works as a membrane fusion site with poroteoliposomes during reconstruction of membrane proteins. We found that it is a new domain formation phenomenon induced by polyunsaturated lipids, and clarified its formation mechanism.
We reconstructed hERG channel, which is a K+ channel distributed in myocardium and involved in action potential generation, to SLB and observed it with AFM. The oligomerization efficiency was quantitatively evaluated based on the AFM images of hERG channel on molecular level.

Free Research Field

界面物理化学

Academic Significance and Societal Importance of the Research Achievements

細胞膜を介した細胞内外での情報・物質・エネルギーのやり取りは、脂質二重膜と膜タンパク質が形成する分子集合体によってなされている。神経伝達・代謝・免疫など、細胞膜を介した輸送や外部認識の異常は疾病に直結することから、化学・生物学分野に加えて医療・創薬分野においても、膜タンパク質と脂質が集合体として働く細胞膜反応の機構を分子レベルで理解することが求められている。本研究で得られた、膜融合サイトとして働く多価不飽和脂質誘起ドメインの形成機構とイオンチャネルの会合状態の直接観察に関する成果は、イオンチャネルを含む膜タンパク質研究のスループット向上に繋と期待される。