biostudies-literatureZhang XNational Institute of Allergy and Infectious DiseasesNIDDK NIH HHSNIAID NIH HHSNational Institute of General Medical SciencesNIGMS NIH HHS3013-3023https://www.ebi.ac.uk/biostudies/studies/S-EPMC9492806biostudies-literatureUnknown17(11)Lysosome-targeting chimeras (LYTACs) offer an opportunity for the degradation of extracellular and membrane-associated proteins of interest. Here, we report an efficient chemoenzymatic method that enables a single-step and site-specific conjugation of high-affinity mannose-6-phosphate (M6P) glycan ligands to antibodies without the need of protein engineering and conventional click reactions that would introduce "unnatural" moieties, yielding homogeneous antibody-M6P glycan conjugates for targeted degradation of membrane-associated proteins. Using trastuzumab and cetuximab as model antibodies, we showed that the wild-type endoglycosidase S (Endo-S) could efficiently perform the antibody deglycosylation and simultaneous transfer of an M6P-glycan from a synthetic M6P-glycan oxazoline to the dACS chemical biologySite-Specific Chemoenzymatic Conjugation of High-Affinity M6P Glycan Ligands to Antibodies for Targeted Protein Degradation.PMC9492806R01AI155716R01 GM096973R01GM096973R01 AI155716R01 DK119937Liu HHe JDonahue TCMuthana MMZhang XWang LXSu LOu CfalseSite-Specific Chemoenzymatic Conjugation of High-Affinity M6P Glycan Ligands to Antibodies for Targeted Protein Degradation.Lysosome-targeting chimeras (LYTACs) offer an opportunity for the degradation of extracellular and membrane-associated proteins of interest. Here, we report an efficient chemoenzymatic method that enables a single-step and site-specific conjugation of high-affinity mannose-6-phosphate (M6P) glycan ligands to antibodies without the need of protein engineering and conventional click reactions that would introduce "unnatural" moieties, yielding homogeneous antibody-M6P glycan conjugates for targeted degradation of membrane-associated proteins. Using trastuzumab and cetuximab as model antibodies, we showed that the wild-type endoglycosidase S (Endo-S) could efficiently perform the antibody deglycosylation and simultaneous transfer of an M6P-glycan from a synthetic M6P-glycan oxazoline to the d2022-01-01T00:00:00Z2022 Nov2025-04-25T19:58:38.801Z2025-04-06T08:14:09.355ZS-EPMC94928063531603210.1021/acschembio.1c00751