Laccases are oxidative enzymes with application in lignolysis and biomass pretreatment. Ionic liquids are a class of solvents, liquid at room temperature, composed entirely of ions. Some ionic liquids are effective solvents for both cellulose and lignin. One major limitation to laccase utilization is substrate solubility; laccase use in ionic liquid/water solutions could have a significant advantage over aqueous systems.
Examples of laccase activity in ionic liquids are available in the literature. However, an investigation of the mechanisms for protein deactivation in polar ionic liquids is largely absent. The study of protein structure in ionic liquids is complicated by the UV absorbance of the solvent, which makes some common spectroscopic techniques impossible.
The present research has begun an investigation into the effect of ionic liquids on laccases by activity and stability assays in the presence of ionic liquids, investigation of the protein active sites by UV spectroscopy, as well as preliminary structural data using differential scanning calorimetry. Activity data for several extremophilic laccases (thermophilic, halophilic) in the presence of ionic liquids is also being collected, and may provide clues for the design of ionic liquid compatible enzymes.