Transferase-Mediated Labeling of Protein N-Termini with Click Chemistry Handles
The E. coli aminoacyl transferase (AaT) can be used to transfer a variety of unnatural amino acids, including those with azide or alkyne groups, to the α-amine of a protein with an N-terminal Lys or Arg. Subsequent functionalization through either copper-catalyzed or strain-promoted click reactions can be used to label the protein with fluorophores or biotin. This method can be used to directly detect AaT substrates or in a two-step protocol to detect substrates of the mammalian ATE1 transferase.
Key wordsN-terminus N-end rule Aminoacyl transferase Protein modification Chemoenzymatic reaction Protein labeling Click chemistry
This work was supported by funding from the University of Pennsylvania and the Searle Scholars Program (10-SSP-214 to EJP). HEG was supported by a summer research fellowship from Eli Lilly.
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