What Are Detergents?

Detergents are amphipathic molecules with a polar portion and a hydrophobic portion. Detergents respond to an aqueous environment following the same principles as do membrane lipids.

What Are the Forms of Detergents?

Detergents can exist in three environments in aqueous media. Detergents have a limited solubility in the aqueous phase, characterized by the CMC, or critical monomer concentration (or critical micelle concentration). Above the CMC, detergents form micelles. In the presence of membranes, detergents can also partition into the membrane. In the latter case, sufficient detergent will lead to transfer of membrane components, including membrane lipids and membrane proteins, into the detergent micelles.

What can Detergents Used for?

Detergent micelles can solubilize membrane proteins from a biological membrane. The choice of a particular detergent that will support solubilization and purification of a particular membrane protein while simultaneously keeping biological function of the protein can be a challenging process.

How Do Detergents Work on Liposomes?

The detergents are used to solubilize the lipids in micellar solution (Walde et al., 2010). Since the detergent protects the hydrophobic part of lipids from interacting with the aqueous solution, micelles are formed instead of liposomal vesicles. The lipids mixture, an aqueous phase that contains hydrophilic drugs, is added to prepare detergent-lipid micelles after drying. Liposomes are spontaneously formed once the detergent is removed by dialysis. Chromatographic techniques have also been employed for the removal of detergents. While this method is very flexible and allows the preparation of a great variety of liposomes, it has some drawbacks of liposome formation. One of these is the use of detergent removal procedures, which are time consuming and might result in removing other hydrophilic components (Meure et al., 2008). Another is suitability of only a few detergents with this method. The most popular detergents used in this method are alkylglycosides, sodium cholate, and alkyloxypolyethylenes.

What Are Detergents for Research Use?

CD Bioparticles offers various detergents for research uses, including Anionic Detergents, Cationic Detergents, Nonionic Detergents, Branched Detergents, Zwitterionic Detergents, and Lipid Mesophase Crystallization. For instance, the Mal (11.1), Catalog:CDLP-A1336, one of the Branched Detergents, is a new class of detergents contain a short, branched alkyl chain at the interface between the polar head and the apolar tail. This design mimics the second aliphatic chain of lipid molecules and reduces water penetration, thereby increasing the hydrophobicity within the interior of the micelle. A detergent architecture of this style allows formation of smaller, more compact micelles which provides improved performance in the stabilization and crystallization of integral membrane proteins.

Another example is the 7.9 MAG (Catalog:CDLP-A1344). This new Lipid detergent may be used for crystallizing membrane proteins by using lipidic mesophases. This method has variously been referred to as the lipidic cubic phase or in meso method. The method has been shown to be quite versatile in that it has been used to solve X-ray crystallographic structures of prokaryotic and eukaryotic proteins, proteins that are monomeric, homo-and hetero-multimeric, chromophore-containing and chromophore-free, and alpha-helical and beta-barrel proteins.

References

1. Yeagle PL. The membranes of cells. Academic Press.
2. Devrim B, Bozkır A. Nanocarriers and Their Potential Application as Antimicrobial Drug Delivery. InNanostructures for Antimicrobial Therapy. Elsevier. 2017, (169-202).
3. Lichtenberg D, Ahyayauch H, et al. The mechanism of detergent solubilization of lipid bilayers. Biophysical journal. 2013, 105(2):289-99.