Generation of reactive oxygen species via inhibition of liver catalase by oxalli-palladium: A spectroscopic and docking study

- Oxali-palladoium can bind to liver catalase.
- Oxali-palladoium quenches the fluorescence intensity of catalase by static quenching mechanism.
- Inhibition of BLC by oxali-palladium increases the content of ROS.
- Oxali-palladium can change the three-dimensional and secondary structure of catalase.

In the present study, the side effects of an anti-cancer compound of oxali-palladium on the function and structure of bovine liver catalase (BLC) were investigated using multiple spectroscopic (fluorescence, circular dichroism (CD) and UV-vis) and molecular docking methods. Results of kinetics study showed a noncompetitive inhibition of the enzyme for oxali-palladium. Addition of various concentrations of oxali-palladium caused a gradual reduction in the intrinsic fluorescence emission intensity of BLC due to quenching the fluorescence of BLC via a static type of quenching mechanism. Also addition of oxali-palladium to the enzyme led to increasing content of α-helix and decreasing of β-pleated sheet and random coil structures. The molecular docking study in well coherent with fluorescence spectroscopy illustrated that there is one binding site for oxali-palladium on bovine liver catalase. Docking results confirmed that static quenching is occurred whereas oxali-palladium is located at the distance of Föster theory. Moreover, docking examination in agreement with binding analyzing revealed electrostatic interaction is dominant driving force in oxali-palladium binding to BLC. According above results, it can be concluded that inhibition of BLC by anticancer drug of oxali-palladium increases the content of reactive oxygen species (ROS) which is one of the mechanisms of different anticancer drugs.

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