Integral membrane proteins are amphipathic molecules crucial for all cellular life. The structural study of these macromolecules starts with protein extraction from the native membranes, followed by purification and crystallisation. Detergents are essential tools for these processes, but detergent-solubilised membrane proteins often denature and aggregate, resulting in loss of both structure and function. In this study, a novel class of agents, designated mannitol-based amphiphiles (MNAs), were prepared and characterised for their ability to solubilise and stabilise membrane proteins. Some of MNAs conferred enhanced stability to four membrane proteins including a G protein-coupled receptor (GPCR), the β2 adrenergic receptor (β2AR), compared to both n-dodecyl-D-maltoside (DDM) and the other MNAs. These agents were also better than DDM for electron microscopy analysis of the β2AR. The ease of preparation together with the enhanced membrane protein stabilisation efficacy demonstrates the value of these agents for future membrane protein research.

Integral membrane proteins play central roles in controlling the flow of information and molecules across membranes. Our understanding of membrane protein structure and function, however, is seriously limited, mainly due to difficulties in handling and analyzing these proteins in aqueous solution. The use of a detergent or other amphipathic agents is required to overcome the intrinsic incompatibility between the large lipophilic surfaces displayed by membrane proteins in their native forms and polar solvent molecules. Here we introduce new tripod amphiphiles displaying favourable behaviours toward several membrane protein systems, leading to enhanced protein solubilization and stabililization compared to both conventional detergents and previously-described tripod amphiphiles.

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An asymmetric MNG, MNG-8,12, provided enhanced stability to human G protein-coupled receptors (GPCRs) compared to the symmetric MNG, MNG-3.

Despite the major biological and pharmacological significance, structural and functional study of membrane proteins remains a significant challenge. A main issue is the isolation of these proteins in a stable and functional state from native lipid membranes. Detergents are amphiphilic compounds widely used to extract membrane proteins from the native membranes and maintain them in a stable form during downstream analysis. However, due to limitations of conventional detergents it is essential to develop novel amphiphiles with optimal properties for protein stability in order to advance membrane protein research. Here we designed and synthesized 1,3,5-triazinecored dimaltoside amphiphiles derived from cyanuric chloride. By introducing variations in the alkyl chain linkage (ether/thioether) and an amine-functionalized diol linker (serinol/ diethanolamine), we prepared two sets of 1,3,5-triazine-based detergents. When tested with several model membrane proteins, these agents showed remarkable efficacy in stabilizing three

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Amphiphiles are critical tools for the structural and functional study of membrane proteins. Membrane proteins encapsulated by conventional head-to-tail detergents tend to undergo structural degradation, necessitating the development of structurally novel agents with improved efficacy. In recent years, facial amphiphiles have yielded encouraging results in terms of membrane protein stability. Herein, we report a new facial detergent (i.e., LFA-C4) that confers greater stability to tested membrane proteins than the bola form analogue. Owing to the increased facial property and the adaptability of the detergent micelles in complex with different membrane proteins, LFA-C4 yields increased stability compared to n-dodecyl-β-d-maltoside (DDM). Thus, this study not only describes a novel maltoside detergent with enhanced protein-stabilizing properties, but also shows that the customizable nature of a detergent plays an important role in the stabilization of membrane proteins. Owing to both synthetic convenience and enhanced stabilization efficacy for a range of membrane proteins, the new agent has major potential in membrane protein research.

Membrane proteins are inherently amphipathic and undergo dynamic conformational changes for proper function within native membranes. Maintaining the functional structures of these biomacromolecules in aqueous media is necessary for structural studies but difficult to achieve with currently available tools, thus necessitating the development of novel agents with favorable properties. This study introduces several new glucose-neopentyl glycol (GNG) amphiphiles and reveals some agents that display favorable behaviors for the solubilization and stabilization of a large, multi-subunit membrane protein assembly. Furthermore, a detergent structure-property relationship that could serve as a useful guideline for the design of novel amphiphiles is discussed.