Evaluation of the Effect of Non-Imidazolium Based Ionic ‎Liquid Triethylammonium ‎Maleate on Uricase Enzyme

Urate oxidase or uricase (UOX) (EC 1.7.3.3) is an globular tetramer oxidoreductase enzyme which lacks cofactor. Much research on this enzyme has been done so far due to its biomedical applications as a therapeutic and diagnostic agent. Urate oxidase catalyzes uric acid degradation and produces allantoin. An imbalance in the excretion of uric acid causes the hyperuricemia. Part of a clinically important diagnostic kit used to measure the concentration of uric acid in the blood is the enzyme uricase. In this research, efforts are made to investigate the effect of triethylammonium maleate (TEAM) ionic liquid on the function of urate oxidase (UOX). Ionic liquids are salts with important properties like high thermal stability, high solvating capacity and high polarity. These salts have been considered in biochemical and biomedical fields. They can also be utilized as a stabilizer for long-term protein storage and they can extend the shelf life of some proteins such as therapeutic or industrial proteins. In this study, we treated the enzyme in different concentrations of triethylammonium maleate ionic liquid. The volume percentages of TEAM in the solvent phase are 1%, 2%, 5%, 10% and 15%. The results indicate that TEAM has a concentration-dependent effect on the activity of UOX enzyme. The use of 5% TEAM ionic liquid increased the enzymatic activity in comparison to untreated enzyme. We concluded that this ionic liquid was able to alter the structure of the uricase in a way that increased the activity and improve its catalytic efficiency of uricase.