Visualization of the process: selenocysteine activates GPX4 in ferroptosis based on a nano-fluorescent probe

Developing accurate methods for visualizing the expressions of proteins during the life process is a hotspot in the biochemical research field. Glutathione peroxidase 4 (GPX4), one type of selenoproteins, was previously identified as a significant ferroptosis-regulated protein. Therefore, a novel approach was established to visualize the activation process of selenocysteine (Sec) toward GPX4 via an Au-Se bonded fluorescent nanoprobe and assisted by western blot analysis. The Au-Se nanoprobe was constructed by selenol-modified peptides for monitoring the concentration changes of Sec. The fluorescence intensity of Sec in confocal fluorescence imaging positively correlates with GPX4’s activation level, proved by western blot analysis in living cells. This study provides an intuitional and visual strategy for predicting the functional expression of GPX4 during the ferroptosis process and offers new directions for the future investigation of proteins’ functional expressions.