engineering of natural proteins. We have previously developed affinity-guided 4-
dimethylaminopyridine (AGD) chemistry as an efficient protein modification method using a
catalytic acyl transfer reaction. However, because of the high electrophilicity of the thioester
acyl donor molecule, AGD chemistry suffers from nonspecific reactions to proteins other than
the target protein in crude biological environments, such as cell lysates, live cells, and tissue …