IL-21 derivatives and variants
The invention provides derivatives of IL-21 or variants thereof, methods of producing such variants, new variants of IL-21, and various methods of using such molecules.
1. A derivative of human interleukin 21 (IL-21) comprising
(a) a human IL-21 polypeptide comprising (i) amino acid residues 32 to 162 of SEQ ID NO:2 or (ii) amino acid residues 30 to 162 of SEQ ID NO:2; and
(b) one or more polymeric molecules linked to the N-terminus of the IL-21 polypeptide through a linker sequence of amino acids comprising Ser-Glu-Ala-Glu- (SEQ ID NO: 16).
2. The human IL-21 derivative of claim 1 , comprising a linker sequence of amino acids comprising Met-Ser-Glu-Ala-Glu (SEQ ID NO: 17).
3. The derivative of claim 1 , wherein the polymeric molecule is a polyethylene glycol (PEG) molecule.
4. The derivative of claim 3 , wherein the PEG molecule has a molecular weight of 5 kDa and is linear or branched.
5. The derivative of claim 3 , wherein the PEG molecule has a molecular weight of 10 kDa.
6. The derivative of claim 3 , which comprisies 3-6 PEG molecules.
7. The derivative of claim 1 , wherein the derivative of human IL-21 has a molecular weight of at least 50 kDa.