Exploring the Interaction of Tartrazine (Food Additive) Dye With Catalase Using Biophysical and Bioinformatics Tools

Tartrazine (synthetic food dye) has been known to exert oxidative stress-related effects, yet its direct impact on antioxidant enzymes like catalase remains poorly understood. This study explores the interaction between tartrazine (synthetic dye) and catalase using various spectroscopic and in silico techniques. UV-visible as well as spectrofluorometric analysis revealed the formation of a catalase-tartrazine complex with a static mode of quenching. A moderate binding affinity ranging from 0.35 to 1.66 × 10⁴ M^-1 was calculated for the complex. Positive ΔH (23.72 kcal/mol) and ΔS (28.57-29.72 kcal/mol) with negative ΔG (-4.84 to -5.99 kcal/mol) suggest the binding process is endothermic and spontaneous, driven by a favorable entropy change. Circular dichroism (CD) indicates the percent α-helix in catalase decreased from 28.06% to 23.29% upon tartrazine binding, indicating some structural alterations. In turn, the catalase activity was decreased (60%) at a higher concentration (100 μM) of tartrazine. Molecular docking analysis identified several active site residues, including Met349, Gly352, Arg353, and Thr360, as key players in the binding process. Further, simulation studies demonstrated that the complex of tartrazine with catalase maintained stability in an aqueous environment. Our findings hinted that the use of additives should be cautious as they may compromise the antioxidant defense mechanisms critical to human health.