Extraction of membrane proteins (GPCRs, ion channels, transporters, viral proteins, etc.) from their native environment for structural or functional studies is a major challenge. It requires destabilizing the lipid bilayer while solubilizing and stabilizing the membrane protein. Conventional detergents are not able to stabilize membrane proteins as efficiently as the lipids found naturally in membranes and this also affects the native state of the membrane proteins. As a result, this will lead to loss of protein activity and functionality. To overcome this issue, CALIXAR has developed surfactant-based approaches to maintain the functional and structural integrity of membrane proteins. It does not require refolding, nor mutagenesis, truncation, or fusion, which can have significant impact on protein conformation. Instead of modifying the protein, our specific approach modifies the chemical environment surrounding the protein.
The CHEM2STAB joint research laboratory – gathering the respective expertise of chemists from Avignon University and biochemists from CALIXAR – has been specifically founded to support the design and synthesis of new molecules able to extract, to stabilize and/or to promote the crystallization of therapeutic membrane protein targets or antigens (without denaturation).
Thanks to CHEM2STAB, we design and synthetize new customized reagents (detergents/surfactants) for membrane protein isolation. Some references are commercially available off-the-shelf:
These molecules are designed to structure the membrane domains of proteins through hydrophobic interactions and a network of salt bridges with the basic residues found at the cytosol-membrane interface of membrane proteins.
Fluorinated poly(tris) and bis-glucose surfactants
Fluorinated surfactants are unable to extract proteins from membrane, but are useful for membrane protein stabilization in subsequent purification steps as they do not strip natural lipids and other co-factors from the proteins. In addition, the bulky fluorinated tails cannot penetrate into the interior and disrupt structure. Fluorinated surfactants often decrease non-specific aggregation and are thought to result in improved distribution on cryo-EM grids and better vitrification for cryo-EM data collection. They are also reported to increase crystallizability.
The bis-glucose compounds have a tetrahedral chiral carbon with two polar headgroups (the glucose moieties) and a long hydrophobic fluorinated tail. In this way, they resemble the neo-pentyl glycol detergents, such as LMNG which has shown some recent success in structural biology.
Check out more details on our commercially available off-the-shelf customized detergents in the following table:
|CALX8||MP Extraction||Powder / Reagent||50mg||1 200 €|
|100mg||1 900 €|
|250mg||3 000 €|
|DDG||MP Extraction||Powder / Reagent||100mg||180 €|
|DDTAC||MP Extraction||Powder / Reagent||250mg||150 €|
|DLAC||MP Extraction||Powder / Reagent||250mg||180 €|
|FLAC6||MP Extraction||Powder / Reagent||50mg||180 €|
|ODG||MP Extraction||Powder / Reagent||100mg||180 €|
|CALXCHOL||MP Stabilization||Powder / Reagent||10mg||450 €|
|50 mg||1 200 €|
|100 mg||1 900 €|
|CALXGLUK||MP Stabilization||Powder / Reagent||10mg||450 €|
|50 mg||1 200 €|
|100 mg||1 900 €|
|DDLAC||MP Stabilization||Powder / Reagent||250mg||150 €|
|FTAC6||MP Stabilization||Powder / Reagent||250mg||150 €|
|FTAC8||MP Stabilization||Powder / Reagent||250mg||150 €|
|The CALIXAR™ C2B Additive Kit||MP Crystalization||Additive / Kit||10 x 50 ul
|496 €||Webpage||Direct Link|
1 Specific quantities can be provided upon request (the annual stock available on the global market for these items is limited and renewed every year)
2 Prices do not include customs and shipping costs
Other new innovative reagents are currently being developed / designed in ours labs. Please contact us using our form for any specific questions.
The CALX8, CALXCHOL and CALXGLUK molecules listed above shall be used for internal research only excluding any direct or indirect commercial uses (under patent rights). If you need to use it for further developments please write us at firstname.lastname@example.org.