Glycoproteins comprising a glycan of the formula (102) are disclosed; wherein b is 0 or 1; the GlcNAc residue optionally fucosylated; and Su(A)x is a sugar derivative comprising x functional groups A, wherein x is 1, 2, 3 or 4 and A is independently selected from the group consisting of an azido group, a keto group, an alkynyl group, a thiol group, a halogen, a sulfonyloxy group, a halogenated acetamido group, a mercaptoacetamido group and a sulfonylated hydroxyacetamido group.
Protein-conjugates having glycoproteins according to the invention conjugated to a molecule of interest (e.g., an active substance) are also disclosed. Examples include modified antibodies, antibody-conjugates, and antibody-drug conjugates (ADCs). Processes for the preparation of the modified glycoproteins according to the invention and methods for the preparation of a protein-conjugate according to the invention are mentioned.