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Acta Biochim Pol

Title:		Laccase activity and stability in the presence of menthol-based ionic liquids
Author(s):		Feder-Kubis J; Bryjak J;
Address:		"Wroclaw University of Technology, Faculty of Chemistry, Department of Chemical Engineering, Wroclaw, Poland. Wroclaw University of Technology, Faculty of Chemistry, Department of Bioorganic Chemistry, Wroclaw, Poland"
Journal Title:		Acta Biochim Pol
Year:		2013
Volume:		20131220
Issue:		4
Page Number:		741 - 745
DOI:
ISSN/ISBN:		1734-154X (Electronic) 0001-527X (Linking)
Abstract:		"Laccases attract attention due to their potential for manufacturing pharmaceutical intermediates from a wide array of phenolic and non-phenolic substrates that are sparingly soluble in water. Because of the high polarity of ionic liquids (ILs), they can dissolve polar and nonpolar compounds and are claimed as 'green' alternative for volatile organic solvents. The main aim of this work was to find water-immiscible ILs suitable for Cerrena unicolor laccase. For that five ILs with bis(trifluoromethanesulfonyl)imide anions coupled with cations derived from natural alcohol - (1R,2S,5R)-(-)-menthol were synthesized, namely: (I) 3-butyl-1-[(1R,2S,5R)-(-)-menthoxymethyl]imidazolium, (II) 1-[(1R,2S,5R)-(-)-menthoxymethyl]-3-heptylimidazolium, (III) 1-[(1R,2S,5R)-(-)-menthoxymethyl]-3-methylpyridinium, (IV) heptyl[(1R,2S,5R)-(-)-menthoxymethyl]dimethylammonium, and (V) decyl[(1R,2S,5R)-(-)-menthoxymethyl]dimethylammonium ions. Laccase activity was tested in buffer saturated with ILs whereas stability tests in biphasic systems lasted 5 days. It was shown that ILs I, III-V did not significantly alter laccase activity (being 90-123% respective to the buffer) whereas IL II decreased reactivity in 20%. Stability tests revealed that ILs I, IV and V increased enzyme stability even more than in the buffer. For mathematical formalization of inactivation courses, isoenzyme model was applied but this model fitted experimental data only for sets obtained in the buffer (control) and in the presence of IL II. In the other cases, first-order reaction model was sufficient. This shows that ILs, even at very low concentrations, influence conformational stability of proteins, which is dependent on the cation structure. In general, the imidazolium (I) and ammonium (IV) salts with shorter alkyl chains supported laccase activity and stability"
Keywords:		Ammonium Compounds/chemical synthesis/chemistry Enzyme Stability/*drug effects Imidazoles/chemical synthesis/chemistry Ionic Liquids/chemical synthesis/*chemistry Laccase/*biosynthesis/chemistry Menthol/chemistry Polyporaceae/enzymology Solvents/chemistry;
Notes:		"MedlineFeder-Kubis, Joanna Bryjak, Jolanta eng Research Support, Non-U.S. Gov't Poland 2013/12/24 Acta Biochim Pol. 2013; 60(4):741-5. Epub 2013 Dec 20"