A Fluorogenic TMP-Tag for High Signal-to-Background Intracellular Live Cell Imaging

摘要: Developed to complement the use of fluorescent proteins in live cell imaging, chemical tags enjoy benefit modular incorporation organic fluorophores, opening possibility high photon output and special photophysical properties. However, theoretical challenge using as opposed for high-resolution imaging is background noise from unbound and/or nonspecifically bound ligand-fluorophore. We envisioned we could overcome this limit by engineering fluorogenic trimethoprim-based (TMP-tags) which fluorophore quenched until binding with E. coli dihydrofolate reductase (eDHFR)-tagged protein displaces quencher. Thus, began building a nonfluorogenic, covalent TMP-tag based on proximity-induced reaction known achieve rapid specific labeling both vitro inside living cells. Here take final step render fluorogenic. In brief, designed trimeric TMP–fluorophore–quencher molecu...