Protein Interface Regulating the Inserting Process of Imidazole Ionic Liquids into the Cell Membrane

J Phys Chem B. 2024 May 9;128(18):4456-4463. doi: 10.1021/acs.jpcb.3c08451. Epub 2024 May 1.

Abstract

Ionic liquids (ILs) have shown promising potential in membrane protein extraction; however, the underlying mechanism remains unclear. Herein, we employed GPU-accelerated molecular dynamics (MD) simulations to investigate the dynamic insertion process of ILs into cell membranes containing membrane proteins. Our findings reveal that ILs spontaneously insert into the membrane, and the presence of membrane proteins significantly decelerates the rate of IL insertion into the membrane. Specifically, the relationship between the insertion rate and inserting free energy exhibits non-monotonic changes, which can be attributed to interfacial effects. The protein-water interface acts as trap for free ions and ionic clusters, while free ions preferentially insert into the membrane from the protein-lipid interface, which limits the insertion rate due to its narrowness. Thus, the insertion rate is governed by a combination of the free energy and interfacial effects. These findings provide valuable insights into the interfacial effects of protein-lipid bilayers and have implications for various biochemical-related applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Membrane* / chemistry
  • Cell Membrane* / metabolism
  • Imidazoles* / chemistry
  • Ionic Liquids* / chemistry
  • Lipid Bilayers* / chemistry
  • Lipid Bilayers* / metabolism
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism
  • Molecular Dynamics Simulation*
  • Thermodynamics
  • Water / chemistry

Substances

  • Ionic Liquids
  • Imidazoles
  • Lipid Bilayers
  • Membrane Proteins
  • imidazole
  • Water