Amberlite XAD-4 is a convenient tool for removing Triton X-100 and Sarkosyl from protein solutions

Amberlite has been shown to be an appropriate material for the adsorption of organic contaminants from aqueous solutions. In addition, Amberlite XAD-2 has been successfully used, as an alternative to Bio-Beads, to remove Triton X-100 from protein solutions, such as from samples of solubilized membrane proteins. However, Amberlite has not been tested as an adsorbent when a mixture of detergents is necessary to solubilize and refold a target protein. Here the authors show that Amberlite XAD-4 can be appropriately used to aid the purification process of proteins solubilized from inclusion bodies with the ternary detergent system consisting of Sarkosyl, Triton X-100 and CHAPS. Method summaryAmberlite XAD-4 can be successfully used to remove detergents that are used to solubilize recombinant proteins overexpressed in Escherichia coli as inclusion bodies. In particular, the authors show that the detergents Sarkosyl, Triton X-100 and CHAPS can be adsorbed by Amberlite XAD-4 when present as a ternary mixture in protein solutions. Remarkably, the adsorption of proteins to Amberlite XAD-4 was found to be negligible. Tweetable abstractThe authors devised a time-saving and cost-effective method for the removal of detergents from proteins refolded after their solubilization from inclusion bodies.