# γ-Cyclodextrin/Genistein Inclusion Complex Catalyzes GPx4-Mediated Reduction of Organic/Inorganic Peroxides: Based on SERS and In Silico Research

## TL;DR

This study shows how a γ-cyclodextrin/genistein complex helps GPx4 reduce harmful peroxides through different mechanisms, using SERS and simulations.

## Contribution

The novel contribution is the discovery of how γ-CD/GEN enhances GPx4 activity and catalyzes peroxide reduction via distinct redox pathways.

## Key findings

- γ-CD/GEN achieves over 40% encapsulation efficiency and disrupts GEN aggregation.
- γ-CD/GEN catalyzes CHP reduction via radical reactions, while H2O2 reduction involves proton transfer.
- Molecular simulations confirm γ-CD/GEN binds to GPx4's active site, enhancing its catalytic activity.

## Abstract

Organic and inorganic peroxides can induce intracellular redox homeostasis. In this study, a γ-cyclodextrin/genistein inclusion complex (γ-CD/GEN) was constructed to systematically elucidate the molecular mechanism by which it catalyzes GPx4-mediated peroxide reduction. The results indicate that the incorporation of γ-CD effectively disrupts the aggregated state of GEN, achieving an encapsulation efficiency (EE) exceeding 40%. Surface-enhanced Raman spectroscopy (SERS) analysis reveals significant differences in the catalytic behavior of γ-CD/GEN toward cumene hydroperoxide (CHP) and hydrogen peroxide (H2O2): the reduction efficiency of CHP depends on both the concentration of γ-CD/GEN and GPx4, whereas the reduction of H2O2 is primarily regulated by the concentration of γ-CD/GEN. Isotope effect studies demonstrate that the reduction of CHP relies more on radical-initiated reactions, while the reduction of H2O2 involves proton transfer, with the differences in reduction rates correlating with their respective redox mechanisms. Molecular docking and molecular dynamics simulations further confirm that γ-CD/GEN can stably bind to the Sec (Cys)-46 site in the active center of GPx4, thereby enhancing its catalytic activity. This study provides a theoretical basis for the development of antioxidant strategies based on the precise regulation of enzyme activity.