Scheme 1. Structure and function of PSGMR.
(a) Molecular structure and schematic illustration of PSGMR with main protease (Mpro). (b) PSGMR is used for Mpro-responsive mitochondrial imaging and selective inhibition of Mpro plasmid transfected or SARS-CoV-2 infected cells. i) PSGMR effectively crosses the cell membrane; ii) Mpro plasmid transfected or SARS-CoV-2-infected cells can produce Mpro; iii) Mpro binds and cleaves the substrate of PSGMR; iv) After being cleaved by Mpro, PSG fragments decrease in size and targeted deliver to the mitochondria; v) The PSG aggregation induces mitochondrial interference and selectively inhibits the growth of SARS-CoV-2-infected cells with strong fluorescence. The potentially charged amino acids are labeled with the charge symbol after Mpro cleavage.