Methods for the solubilisation of membrane proteins: the micelle-aneous world of membrane protein solubilisation

Abstract

The solubilisation of membrane proteins (MPs) necessitates the overlap of two contradictory events; the extraction of MPs from their native lipid membranes and their subsequent stabilisation in aqueous environments. Whilst the current myriad of membrane mimetic systems provide a range of modus operandi, there are no golden rules for selecting the optimal pipeline for solubilisation of a specific MP hence a miscellaneous approach must be employed balancing both solubilisation efficiency and protein stability. In recent years, numerous diverse lipid membrane mimetic systems have been developed, expanding the pool of available solubilisation strategies. This review provides an overview of recent developments in the membrane mimetic field, with particular emphasis placed upon detergents, polymer-based nanodiscs and amphipols, highlighting the latest reagents to enter the toolbox of MP research.

A Critical Evaluation of Detergent Exchange Methodologies for Membrane Protein Native Mass Spectrometry

“…3 Generally, MPs must be preserved within a mimetic in order to preserve their structural integrity. 4,5 Typically, MPs are placed into a detergent micelle, wherein their hydrophobic portions are shielded by detergent molecules. 6 Other mimetics can be used, including bicelles, nanodiscs, liposomes, lipodisqs, and amphipols.…”

Synthesis of well‐defined methacrylate copolymers and their use for stabilizing membrane proteins

“…In addition, detergent micelles can be detrimental for structural and biophysical analyses. Therefore, it has been necessary to develop novel tools for the extraction of membrane proteins, and amphiphilic polymers appeared as a promising alternative 2 . Among these polymers, amphipols (APols) 3 and non‐ionic amphipols (NAPols) 4 are interesting tools to keep membrane proteins in their native form.…”

“…Therefore, it has been necessary to develop novel tools for the extraction of membrane proteins, and amphiphilic polymers appeared as a promising alternative. 2 Among these polymers, amphipols (APols) 3 and non-ionic amphipols (NAPols) 4 are interesting tools to keep membrane proteins in their native form. Nevertheless, at variance with detergents, amphipols are not efficient for disrupting membranes, so membrane proteins must first be extracted with classical detergents before being transferred along with their endogenous residual lipids into micelles of APols to form a stable complex.…”

Combinatorial synthesis enables scalable designer detergents for membrane protein studies

“… 8 For decades, detergents are being routinely applied in membrane protein purification. 15 However, it still remains puzzling how the molecular structure of detergents affects purification outcomes. Here, we harness the potential of scalable hybrid detergents to understand how detergent polarity and shape affect critical purification parameters, including protein yields and activity.…”