General and Robust Chemoenzymatic Method for Glycan-Mediated Site-Specific Labeling and Conjugation of Antibodies: Facile Synthesis of Homogeneous Antibody–Drug Conjugates

• DOI: 10.1021/acschembio.1c00597
• Publication Date: 2021-09-27T21:59:55Z
• Authors: Xiao Zhang; Chong Ou; Huiying Liu; Sunaina Kiran Prabhu; Chao Li; Qiang Yang; Lai-Xi Wang
• Keywords: Conjugate

Site-specific labeling and conjugation of antibodies are highly desirable for fundamental research developing more efficient diagnostic therapeutic methods. We report here a general robust chemoenzymatic method that permits one-pot site-specific functionalization antibodies. A series selectively modified disaccharide oxazoline derivatives were designed, synthesized, evaluated as donor substrates different endoglycosidases antibody Fc glycan remodeling. found among several tested, wild-type endoglycosidase from Streptococcus pyogenes serotype M49 (Endo-S2) exhibited remarkable activity in transferring the functionalized disaccharides carrying site-selectively azide, biotin, or fluorescent tags to without hydrolyzing resulting transglycosylation products. This discovery, together with excellent deglycosylation Endo-S2 on recombinant antibodies, allowed direct manner need intermediate enzyme separation. The introduction varied numbers azide groups enabled synthesis homogeneous antibody–drug conjugates (ADCs) precise control drug-to-antibody ratio (DAR) ranging 2 12 via copper-free strain-promoted click reaction. Cell viability assays showed ADCs higher DARs potent killing antigen-overexpressed cells than lower DARs. new is expected find applications not only but also cell labeling, imaging, diagnosis.