Aspirin in retrieving the inactivated catalase to active form: Displacement of one inhibitor with a protective agent.

Aspirin as a potential drug is able to bind to different targets and also could affect on the binding process of other ligands. In the present work, aspirin was considered as a protective agent to retrieve the inactivated catalase by farnesiferol C (FC) through displacement manner. The catalytic assessment revealed that aspirin is able to remarkably retrieve the activity of FC-catalase from 4.2 ± 0.2% to 98 ± 0.1% compare to the control sample. Furthermore, displacement study and CD spectroscopy indicated that aspirin could reduce the stability of FC-catalase complex. Based on the obtained data, it is shown that the binding of aspirin to catalase led to decrease the affinity of catalase to the inhibitor. The releasing analysis of FC from the complex showed that the dissociation constant (Kd) of FC-catalase was increased, considerably from 8.9 ± 0.2 μM to 256 ± 01 μM in the presence of aspirin at 298 K. Also, molecular simulation proved the instability of FC-catalase following the binding of aspirin to the complex.