Creative Biolabs has established a leading membrane protein technique platform offering a full range of featured services and products. With the spirit of progress and dedication, we now provide the innovative service of membrane proteins reconstituted into amphipols for various research applications and demands.
Although solubilization and stabilization of membrane proteins by detergents is the most general and widely applied approach, there can be risks that use of detergents may cause protein misfolding, loss of stability and activity. To overcome these problems, a novel class of short amphipathic polymers amphipols (APols) are designed to tightly bind membrane proteins and keep them soluble and stable in more native state.
Among various kinds of amphipols, the most commonly used member for membrane protein studies is A8-35, with very high water solubility (>200 g/L). It is synthesized from low MW polyacrylic acid precursors by forming amide bonds between the carboxylic groups and octylamine or isopropylamine (Fig. 1). A8-35 is composed of a short polyacrylate chain (∼70 residues) which is grafted with ∼17 octylamine and∼28 isopropylamine. The other ∼25 free acid groups are charged in aqueous solutions guaranteeing the polymer’s high water solubility. The octylamide moieties are responsible for the hydrophobic characteristic.
Fig. 1 Chemical structures of A8-35.
Membrane proteins are usually extracted from membranes using detergents and subsequently transferred to amphipol solutions (as shown in Fig. 2a). When added to the micellar solution at neutral or alkaline pH, amphipol is either mixed with detergents in micelles or binding on the hydrophobic surface of membrane proteins. This way, membrane proteins will be wrapped in small amphipol-detergent complexes. Afterwards, detergent components can be removed by incubation with polystyrene beads. Notably, the ability of amphipols to stabilized membrane proteins is not restricted by membrane protein size, secondary structure composition, aggregation state or distribution of hydrophilic and hydrophobic surfaces. Besides, it is also very convenient to convert protein-amphipol complex to another reconstitution formats (Fig. 2b).
Fig. 2 Models for transferring a membrane protein (a) from a detergent solution to an amphipol and (b) from an amphipol to other surfactants.
Advantages of membrane protein stabilized in amphipols include:
Besides membrane protein production using amphipols service, Creative Biolabs can also offer various high-quality services including but not limited to the following:
Let us know your needs, and we will strive our best to present you most satisfactory service. Please feel free to inquire us to get more details.