EndoS and EndoS2 can be used to remodel the N -glycan on therapeutic IgG antibodies using a chemoenzymatic approach. First, wild-type EndoS and/or EndoS2 hydrolyze a variety of glycoforms present in the Fc region according to their N -glycan specificity. Next, other enzymes can be used to hydrolyze specific carbohydrate moieties, e.g. fucose which absence improves the binding to FcRIIIa and the antibody-dependent cellular cytotoxicity (ADCC) properties of the antibody. Last, EndoS D233Q and EndoS2 D184M glycosynthase mutants facilitate the transfer of a glycan-oxazoline donor with a defined glycoform to the Fc region of IgG antibodies. The dotted shapes represent that carbohydrate may or may not be present, indicating the high heterogeneity of the N -glycan which impact the functionality, immunogenicity and pharmacokinetic of the antibody.
