Charged Biological Membranes Repel Large Neutral Molecules by Surface Dielectrophoresis and Counterion Pressure

Published

January 30, 2024

Author(s)

Marcel Aguilella-Arzo, David Hoogerheide, Mathieu Doucet, Hanyu Wang, Vicente Aguilella

Abstract

Macromolecular crowding is the usual condition of cells. The implications of the crowded cellular environment for protein stability and folding, protein-protein interactions, and intracellular transport drive a growing interest in quantifying the effects of crowding. While the properties of crowded solutions have been extensively studied, less attention has been paid to the interaction of crowders with the cellular boundaries, i.e. membranes. However, membranes are key components of cells and most subcellular organelles, playing a central role in regulating protein channel and receptor function by recruiting and binding charged and neutral solutes. While membrane interactions with charged solutes are dominated by electrostatic forces, here we show that significant charge-induced forces also exist between membranes and neutral solutes. Using neutron reflectometry (NR) measurements and molecular dynamics (MD) simulations of polyethylene glycol (PEG) polymers of different molecular weights near charged and neutral membranes, we demonstrate the role of surface dielectrophoresis and counterion pressure in repelling PEG from charged membrane surfaces. The resulting depletion zone is expected to have consequences for drug design and delivery, the activity of proteins near membrane surfaces, and for transport of small molecules along the membrane surface.

Citation

Journal of the American Chemical Society

Volume

146

Issue

4

Pub Type

Journals

Download Paper

https://doi.org/10.1021/jacs.3c12348

Local Download

Keywords

neutron reflectometry, dielectrophoresis, counterion pressure, molecular dynamics simulations, macromolecular crowding

Citation

Aguilella-Arzo, M. , Hoogerheide, D. , Doucet, M. , Wang, H. and Aguilella, V. (2024), Charged Biological Membranes Repel Large Neutral Molecules by Surface Dielectrophoresis and Counterion Pressure, Journal of the American Chemical Society, [online], https://doi.org/10.1021/jacs.3c12348, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=956893 (Accessed October 14, 2025)