A method for conjugation of glycosylated Fc-containing proteins is described. The method comprises carbamate chemistry performed and neutral pH or below and the resulting Fc-containing protein are expected to retain tertiary structure and therefore Fc-related bioactivity such as FcR binding, the ability to bind Clq, in addition to retaining ligand binding capabilities related to the incorporation of a ligand binding peptide or other polypeptide which has binding specificity. The method is exemplified using an erythropoietin-mimetic peptide fused to a human IgG1 antibody constant domain comprising a hinge, CH2 and CH3.