Effect of Chelating Agents on Cofactors of Catecholase Enzyme

This study aimed to investigate the effect of chelating agents on catecholase enzyme activity and identify the role of cofactors in the catechol to benzoquinone reaction. Catecholase is an essential enzyme in plants' defense mechanisms against injury and pathogens. It was hypothesized that the enzyme activity would be negatively impacted by the presence of citric acid and phenyl thiourea (PTU), which bind to copper. To test our hypothesis, we conducted an experiment using four tubes, each treated with different chelating agents or serving as a control. Enzyme activity was assessed by measuring absorbance changes and the resulting color of the reaction products. The results demonstrated a decrease in catecholase activity in the presence of PTU and citric acid, supporting our hypothesis and suggesting copper as a crucial cofactor in the catecholase enzyme reaction. Furthermore, the lower pH induced by citric acid appeared to have a negative impact on enzyme activity, aligning with previous research indicating that catecholase functions optimally at a pH of 8. These findings contribute to our understanding of the role of cofactors in catecholase enzyme function and the factors that affect its activity, providing valuable insights for future research and potential applications in agriculture and plant protection.