Effects of membrane tension and membrane potential on the function of antimicrobial peptides and cell-penetrating peptides and their mechanisms

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03193
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 43040:Biophysics-related
• Research Institution: Shizuoka University
• Principal Investigator: Yamazaki Masahito 静岡大学, 電子工学研究所, 教授 (70200665)
• Co-Investigator(Kenkyū-buntansha): 岡 俊彦 静岡大学, 電子工学研究所, 准教授 (60344389)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 抗菌ペプチド / 細胞透過ペプチド / 膜張力 / 膜電位 / ポア形成 / ペプチドのベシクル内侵入 / ペプチドの膜透過 / 浸透圧

Outline of Final Research Achievements

We investigated the effects of membrane potential and membrane tension on the functions of antimicrobial peptides (AMPs) and cell-penetrating peptides (CPPs) and their interactions with membranes using the single giant unilamellar vesicle (GUV) method. We found that as negative membrane potential in single GUVs increases, the rate constant of AMP-induced pore formation and local rupture increases and the rate of entry of CPPs into the GUV lumen without pore formation increases. By revealing these effects on the elementary processes, we proposed their mechanisms. We estimated membrane tension in a GUV under osmotic pressure experimentally, and using this method, we revealed the effect of osmotic pressure on the AMP-induced pore formation quantitatively. We also examined the interaction of AMPs with single bacterial cells and single spheroplasts, and revealed the effect of membrane potential on these interactions.

Free Research Field

生体膜の生物物理学

Academic Significance and Societal Importance of the Research Achievements

抗菌ペプチド(AMP) や細胞透過ペプチド(CPP) の機能や膜との相互作用に対する膜電位や膜張力の効果は今まで十分に解明されていなかった。本研究では、AMPやCPPと膜との相互作用や機能の素過程が解明できる単一巨大リポソーム（GUV）法を用いて、それらに対する膜電位や膜張力の効果を研究できる方法を新しく開発した。それらの方法を用いて、AMPによる膜中のポア形成や膜損害、およびCPPのGUV内腔への侵入などに対する膜電位や膜張力の効果を明らかに、それらの素過程の解明によりメカニズムを明らかにした。