Refolding of Laccase in Dilution Additive Mode with Copper-Based Ionic Liquid

• Published in: Applied biochemistry and biotechnology Vol. 171; no. 5; pp. 1289 - 1298
• Main Authors: Bae, Sang-Woo, Ahn, Kihun, Koo, Yoon-Mo, Ha, Sung Ho
• Format: Journal Article
• Language: English
• Published: Boston Springer-Verlag 01.11.2013; Springer US; Springer Nature B.V
• Subjects: Biochemistry; Biotechnology; Chemical engineering; Chemistry; Chemistry and Materials Science; Coenzymes - chemistry; Copper - chemistry; Coriolus versicolor; Enzymes; Fungal Proteins - chemistry; Hot Temperature; hydrophobicity; ionic liquids; Ionic Liquids - chemistry; Kinetics; laccase; Laccase - chemistry; Protein folding; Protein Refolding; Proteins; salts; temperature; Trametes - enzymology; Trametes versicolor; urea; Dilution refolding; Copper-containing protein; Metalloenzyme; Protein refolding; Ionic liquid; Laccase
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-013-0422-9

Ionic liquids (ILs) are molten salts which do not crystallize at room temperature. Tunable physicochemical properties of ILs including hydrophobicity and polarity facilitate their applications in many biological processes. In this study, a copper-based IL was employed in order to enhance the refolding efficiency of laccase from Trametes versicolor which requires copper as a cofactor. When 1-ethyl-3-methylimidazolium trichlorocuprate ([EMIM][CuCl₃]) was added to refolding buffer instead of urea, the laccase refolding yield was improved more than 2.7 times compared to the conventional refolding buffer which contains urea. When the refolding of laccase was carried out at different temperatures (4, 25, and 37 °C), the highest refolding yield was obtained at 25 °C. At low temperature, two conflicting effects, i.e., suppression of the aggregate formation and decrease of folding rate, influence the protein refolding. In contrast, a copper-based IL did not enhance the refolding of lysozyme, a non-copper-containing protein. From these results, we can conclude that this copper-based IL, [EMIM][CuCl₃], was exclusively effective on the refolding process of a copper-containing protein.