Patent ID: 7341720

Claim:
A conjugate comprising: (1) a therapeutic glycoprotein (G), (2) a masking moiety (M) covalently linked to an amino acid residue of the glycoprotein through a first linker (L 1 ), and (3) a targeting moiety (T) covalently linked to the masking moiety through a second linker (L 2 ), wherein: the conjugate has formula G(L 1 -M(L 2 -T) n ) m wherein 2≦m≦16, and n <1 or 1<n≦20, the therapeutic glycoprotein is α-galactosidase A, the masking moiety is polysialic acid (PSA), and L 1 and L 2 each comprise a disulfide, and wherein the glycoprotein is released from the conjugate under lysosomal conditions.