Site-specific protein PEGylation catalyzed by endo-β-N-acetylglucosaminidase

We demonstrated a novel site-specific method of protein PEGylation that is catalyzed by endo-β-N-acetylglucosaminidase (ENGase) with PEGylated oxazoline (1) as a donor. PEGylation via transglycosylation using 1 proceeded smoothly to GlcNAc compounds such as p-nitrophenyl N-acetylglucosaminide and RNase B derivatives.