NCL reaction scheme. The reaction mixture containing 1
mM CysPA
(1), 1 mM peptide-Nbz (2), 5 mM 4-MPAA,
and 5 mM DTT in PBS was reacted at pH 7.4 for 24 h at 37 °C to
generate peptide-functionalized PA (3). The peptides
used in the reaction are RGDS (2a,3a), biotin-RGDS
(2b,3b), and RGES (2c,3c).