Unveiling Eukaryotic Membrane Proteins in High Resolution Using Peptide Solubilization

Abstract

Integral membrane proteins are vital for numerous biological functions and are typically studied using X-ray crystallography and cryo-electron microscopy (cryo-EM). However, these techniques require the extraction of target membrane proteins from their native membranes using detergents, which might disrupt the lipid environments and alter protein behavior. In this study, we present a novel method for solubilizing membrane proteins using a peptide, thereby eliminating the need for detergents throughout the procedure. We demonstrate that the 4F peptide effectively solubilizes a range of membrane proteins and complexes into peptidiscs, while preserving their functionality and structural integrity. Converting these peptidiscs into nanodiscs further enhances particle homogeneity and facilitates high-resolution structural determination of membrane proteins. Our findings highlight the potential of membrane-solubilizing peptides to advance membrane protein research. HighlightsO_LI4F peptide can effectively solubilize eukaryotic membrane proteins C_LIO_LI4F-peptidisc can be converted to MSP-wrapped nanodisc for high resolution cryo-EM studies C_LIO_LI4F solubilization can preserve endogenous ligands bound to the target membrane protein C_LI