Enzymatic behavior of bovine liver catalase in aqueous medium of sugar based deep eutectic solvents

Abstract

Natural deep eutectic solvents are novel green solvent media with outstanding characteristic features which are used in many enzymatic reaction studies in the last decade. There are many possible combinations of natural materials which lead to an individual deep eutectic solvent with unique features. Thereby, they are suitable solvent media to study the functionality of biological macromolecules like enzymes.In current study, the enzymatic efficiency of bovine liver catalase (BLC) was investigated in three sugar based deep eutectic solvents by using various spectroscopic methods of Uv-Visible, fluorescence and circular dichroism (CD). Combination of Glucose, Fructose and Sucrose with Choline chloride as vitamin B4, were used to make three different sugar-based deep eutectic solvents.Kinetic studies was demonstrated that formation of complex hydrogen bond network between Choline chloride and sugar components in Glucose and Sucrose based aqueous deep eutectic solvents of 50% and 60% concentrations keep the catalase activity near to 50%.Fluorescence analysis revealed that catalase fluorophore is fully quenched in 30% concentrated GCH (Glucose: Choline chloride: Water) and SCH (Sucrose: Choline chloride: Water) which is a sign of considerable tertiary structure changes. Also even the CD results which showed that α-Helical content decrease considerably in this concentration but enzyme is 80% active in both Glucose and Sucrose based deep eutectic solvents.From Hofmeister series viewpoint, synergistic relation between Choline chloride component as a well-known chaotropic molecule and sugar components as chaotropes in lower concentrations and kosmotropes in higher concentrations is influential factor on catalase enzyme activity trend in this research study.