Provided are binding polypeptides (e.g., antibodies), and effector moiety conjugates thereof, comprising a CH1 domain (e.g., a human IgG1 CH1 domain), wherein the CH1 domain has an engineered N-linked glycosylation site at amino acid position 114, according to Kabat numbering. Also provided are nucleic acids encoding the antigen-binding polypeptides, recombinant expression vectors and host cells for making such antigen-binding polypeptides. Methods of using the antigen-binding polypeptides disclosed herein to treat disease are also provided.