Purpose: The study on the interaction between various compounds and macromolecules such as enzymes has been very important for monitoring the alteration of structural and functional properties of them. Resveratrol (3, 5, 4-trihydroxy-stilbene; RES) is a biologically active phytoallexin found in grapes and other food products. This article shows an interaction of native bovine liver catalase (BLC) with natural antioxidant product, trans resveratrol (tRES) using multispectroscopic methods. Methods: The interaction between BLC and tRES is performed using UV-vis absorption, fluorescence and circular dichroism (CD) spectroscopy and molecular docking study. Results: In vitro kinetic studies indicated that tRES can decrease BLC activity through uncompetitive inhibition. The results of spectroscopic methods represented that the binding of tRES with BLC can change the micro-region around aromatic amino acids (tryptophan (Trp) and tyrosine (Tyr)) and quench intrinsic fluorescence of BLC by a static mechanism. According to fluorescence quenching data analysis, it was revealed that tRES has one binding site on BLC. The thermodynamic parameters were obtained, which demonstrated that tRES can bind to BLC by van der Waals forces and hydrogen bonds. Molecular docking results indicated that tRES binds to BLC away from heme group and near to the Tyr 324 and Phe 265. These results are in agreement with the experimental results. Conclusion: The inhibitory effect of tRES on BLC demonstrated that excessive consumption of the antioxidants could be resulted in hazardous effects.
Keywords: Bovine liver catalase; Molecular docking; Spectroscopy; Trans resveratrol; Uncompetitive inhibition.