Mempro™ Detergent-Free Annexins Production

Based on the comprehensive protein engineering platform established through years of experiences, scientists form Creative Biostructure can provide advanced custom Mempro™ annexins production services using detergent-free expression system.

Annexins are a group of membrane binding proteins, which must be able to bind in a Ca2+-dependent manner and contain a conserved structural element called annexin repeat, a 70 amino acids residues in length. Annexin repeat is highly α-helical and slightly curved disc that has a surface containing the Ca2+- and membrane-binding sites. It has been shown that annexins play crucial roles in vesicle transport (such as exocytosis and endocytosis) and calcium ion channel formation. Traditional techniques for membrane protein production require extraction from the membrane into detergent micelles. However, the significant drawback of detergent is that can induce conformational changes on the proteins. Our alternative detergent-free expression system can best preserve the native conformation of annexins for further functional analysis.

Figure 1. The structural model of human annexin III. (OPM database)

Creative Biostructure has extensive experience in high-yield annexins production in detergent-free protein expression system, we can perform various strategies for Mempro™ detergent-free annexins production, including:

• Mempro™ annexins production using nanodiscs

  Nanodiscs are the self-assembled technique to stabilize transmembrane proteins removed from the membrane by membrane scaffold proteins (MSPs) without detergent. Creative Biostructure can reconstitute annexins into nanodiscs in detergent-free procedure: Expressing the annexins in the cell-free expression system with the addition of pre-assembled nanodiscs.

• Mempro™ annexins production using amphipols

  The amphipathic amphipols have the ability to enwrap transmembrane proteins, allowing them to stay folded. Creative Biostructure can apply A8-35 to solubilize annexins during purification and stabilization processes.

• Mempro™ annexins production using poly (styrene-co-maleic acid) lipid particles (SMALPs)

The SMALPs can be self-assembled by the simple addition of the SMA co-polymers. At neutral or alkaline pH, The disc-like structure assembles itself, encapsulating annexins in a formation amenable to be purified.

These novel detergent-free techniques for integral membrane protein production can be obtained easily, and enabling more comprehensively structural and functional studies.

Creative Biostructure provides other various Mempro™ membrane protein production services. Please feel free to contact us for a detailed quote.

References:
C. Tribet, et al. (1996). Amphipols: Polymers that keep membrane proteins soluble in aqueous solutions. Proc Natl Acad Sci U. S. A. 93: 15047-15050.
M. Jamshad, et al. (2011). Surfactant-free purification of membrane proteins with intact native membrane environment. Biochem. Soc. Trans., 39: 813-818.
U. Rescher and V. Gerke (2004). Annexins - unique membrane binding proteins with diverse functions. J. Cell Sci., 117: 2631-2639.
V. Gerke and S. E. Moss (2002). Annexins: from structure to function. Physiol. Rev., 82(2): 331-371.