Enhancing the efficiency of sortase–mediated ligations through nickel–peptide complex formation

A modified sortase A recognition motif containing a masked Ni2+-binding peptide was employed to boost the efficiency of sortase-catalyzed ligation reactions. Deactivation of the Ni2+-binding peptide using a Ni2+ additive improved reaction performance at low to equimolar ratios of the glycine amine nucleophile and sortase substrate. The success of this approach was demonstrated with both peptide and protein substrates.