Site-Specific Anchoring a Luminescent Tag in a Protein with Non-Emissive Iridium(III) Complex

Chembiochem. 2024 Jan 3:e202300798. doi: 10.1002/cbic.202300798. Online ahead of print.ABSTRACTSite-specific modification of proteins with synthetic fluorescent tag effectively improves the resolution of imaging, and such a labeling method with negligible three-dimensional structural perturbations and minimal impact on the biological functions of proteins is of high interest to dissect the high-resolution activities of biomolecules in complex systems. In this work, several non-emissive iridium(III) complexes [Ir(C^N)2(H2O)2]+OTF- (C^N denotes various cyclometalated ligands) were designed and synthesized. These complexes were tested for attaching a protein by coordinating to H/X (HisMet, HisHis, and HisCys) that are separated by i and i+4 in a-helix. Replacement of the two labile water ligands in the iridium(III) complex by a protein HisHis pair increases the luminescent intensity up to over 100 folds. The labeling approach has been demonstrated in a highly specific and efficient manner in a number of proteins, and it is also feasible for labeling target proteins in cell lysates.PMID:38169080 | DOI:10.1002/cbic.202300798

Source: Chembiochem - January 3, 2024 Category: Biochemistry Authors: Shu-Li Guo Yu-Hao Xiao Bin-Bin Pan Xun-Cheng Su Source Type: research