Lysine-targeting covalent modification of His-tag fused membraneproteins in live cells

摘要

Covalent modification of proteins under crude biological conditions is of interest toexplore protein dynamics and function.Although tools such as protein based self-labelingtags (e.g.SNAP-tag,Halo-tag) have been well developed to achieve selective proteinlabeling in live cells,their large size often compromises the natural function and behavior oftarget protein.To sidestep this problem,we previously developed a reactive short peptidetag-probe pair system1 employing the affinity between Ni(II)-NTA/His6 tag to facilitate theproximity driven SN2 reaction between Cys residue in the tag and chloroacetamide reactioncenter.However,oxidation of Cys residues often inhibits the labeling reaction,which limitsits general use in live-cell contexts.