Folding and stabilizing membrane proteins in amphipol A8-35

Area of Science:

• Biochemistry
• Structural Biology
• Drug Discovery

Background:

• Membrane proteins (MPs) are crucial drug targets involved in cellular processes and diseases.
• In vitro study of MPs is challenging due to overexpression, extraction, and purification difficulties.
• Folding MPs from inclusion bodies (IBs) is a significant hurdle in structural and functional analysis.

Purpose of the Study:

• To review the properties of amphipols (APols), specifically A8-35, for folding membrane proteins.
• To summarize studies utilizing A8-35 for MP folding and complex formation.
• To provide practical methods for folding and trapping MPs using APols.

Main Methods:

• Utilizing amphipathic polymers (APols) as a novel medium for MP folding.
• Employing APol A8-35 for the stabilization and folding of both α-helical and β-barrel MPs.
• Describing folding and trapping protocols for MPs.

Main Results:

• APols enhance MP stability in aqueous solutions compared to detergents.
• High folding yields of MPs can be achieved using APols.
• APol A8-35 demonstrates effectiveness in folding various types of MPs.

Conclusions:

• Amphipols provide an effective strategy for folding membrane proteins, overcoming previous limitations.
• The use of APols, particularly A8-35, facilitates structural and functional studies of MPs.
• This approach holds promise for advancing drug discovery targeting membrane proteins.