Patent ID: 7173003

Claim:
A cell-free, in vitro method of forming a covalent conjugate of a granulocyte colony stimulating factor (G-CSF) peptide, said peptide having the formula: wherein AA is a terminal or internal amino acid residue of said peptide; X 1 â€”X 2 is a saccharide covalently linked to said AA, wherein X 1 is a first glycosyl residue; and X 2 is a second glycosyl residue covalently linked to X 1 , wherein X 1 and X 2 are selected from monosaccharyl and oligosaccharyl residues; said method comprising: (a) removing X 2 or a saccharyl subunit thereof from said peptide, thereby forming a truncated glycan; and (b) contacting said truncated glycan with at least one glycosyltransferase and at least one modified sugar donor under conditions suitable for said at least one glycosyltransferase to transfer a modified sugar moiety of said at least one modified sugar donor to said truncated glycan, wherein said modified sugar moiety comprises at least one modifying group which is a water-soluble polymer, thereby forming said covalent conjugate of said G-CSF peptide.