earticle

영어

High level expression of recombinant protein often leads to the accumulation of inactive and improperly folded proteins as insoluble aggregates in the host cell, so-called inclusion bodies (IBs). Thus, an additional protein refolding process is required to convert IBs to water-soluble active protein. Ionic liquids (ILs) are organic salts composed of anion and cation. In particular, ILs which do not crystallize at room temperature are called room temperature ionic liquids (RTILs). Tunable physiochemical properties of RTILs such as hydrophobicity and polarity leads the expansion of their applications in various chemical and biological processes.1 Recently Summers and Flowers applied ethylammonium nitrate (EAN) on dilutionbased refolding of lysozyme and achieved 90% of refolding yield by suppressing the aggregation of denatured protein.2 In this study, the effect of hydrophobicity and substituted anions of ILs as refolding additives on lysozyme refolding was investigated. Furthermore, lysozyme refolding process was optimized in terms of the refolding time, concentration of RTILs and operating temperature. Refolding yield was proportionally decreased with alkyl chain length of RTILs. MS-based RTILs was more effective than BF4-based RTILs. The refolding yields of lysozyme were improved over 100 % and 81 % when 0.5 M and 1.0 M of MS- and BF4-based RTIL was added in refolding buffer, respectively. The optimum refolding temperature was found at 25℃.