Mesophilic alcohol dehydrogenase behavior in imidazolium based ionic liquids

The use of ionic liquids to replace organic solvents in biocatalytic processes has recently gained much attention. Despite the wide applications of oxidoreductases, there are few reports of their catalyzed reaction in ionic liquid. We have investigated the influence of four water miscible ionic liquids on the activity, stability and structure of the mesophilic alcohol dehydrogenase from yeast. Upon changes in ionic liquids concentration, both activity and stability of the enzyme were affected. As the concentration of ionic liquids increased, K-m increased while k(cat) decreased. Associated conformational changes caused by ILs (150 mM) were monitored using fluorescence technique. Finally, the effects of Its cations and anions on the enzyme activity and stability in aqueous IL mixtures were discussed. (C) 2011 Elsevier B.V. All rights reserved.