Reversible Switch of Artificial Selenoenzyme Activity Modulated by Metal Ion-Induced Protein Nano-Assemblies

In this study, we used computational design and protein engineering to modify stabilizing protein 1 to mimic glutathione peroxidase (GPx), and constructed a reversible protein-assembled nanoscale artificial selenidase based on Ni2+-response. Its unique glutathione substrate recognition site and spatial orientation of the Se active center endow it with high GPx activity. The experimental results showed that the spatial barrier formed by Ni2+-induced assembly can inhibit enzyme activity, and EDTA can dissociate and restore activity. And the reversible protein assembly system is robust after multiple cycles, demonstrating the potential of this "intelligent" artificial selenoenzymatic nanomaterials for controllable catalytic applications in biomedicine.