More than 50 detergents including acylated amino acid derivatives were screened for their ability to solubilize and refold recombinant proteins expressed as inclusion bodies Two model proteins human interleukin-6 and microbial transglutaminase were solubilized by these detergents and the solubilized proteins were rapidly diluted for testing their solubilization and refolding effectiveness Long chain-acylated amino acid derivatives having dicarboxylic acid moieties were found to be superior to others under the conditions tested In particular lauroyl L-glutamate (C12-L-Glu) showed the highest recovery of the native proteins The effectiveness of dilution refolding was greatly improved by adding aggregation suppressive arginine into the refolding solvents To gain understanding how this detergent works interactions between detergents and proteins were examined using spectroscopic and native gel electrophoretic analyses showing ideal properties for C12-L-Glu as a solubilzing agent le highly reversible nature of the detergent binding to the model globular proteins and of the conformational changes These properties most likely have contributed to the effective protein solubilzation and refolding of inclusion bodies using C12-L Glu and arginine (C) 2010 Elsevier Inc All rights reserved