Modified human four helical bundle polypeptides and their uses
Modified human four helical bundle (4HB) polypeptides and uses thereof are provided.
1. An isolated four helical bundle (4HB) polypeptide chosen from the group consisting of human growth hormone, interferon, erythropoietin, and granulocyte cell stimulating factor, comprising a ribosomally incorporated para-acetyl-phenylalanine within the C-D loop of the 4HB polypeptide, wherein the 4HB polypeptide with para-acetyl-phenylalanine has at least a 2-fold increased serum half-life over the wild type 4HB polypeptide.
2. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide further comprises an amino acid substitution made within the N-terminus, C-terminus, A-B loop, B-C loop, C-D loop or, when present, the E helix or D-E loop.
3. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide further comprises an amino acid substitution, addition or deletion that modulates affinity of the 4HB polypeptide for a 4HB receptor.
4. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide further comprises an amino acid substitution, addition or deletion that increases the stability or solubility of the 4HB polypeptide.
5. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide further comprises an amino acid substitution, addition or deletion that increases the expression of the 4HB polypeptide in a recombinant host cell or increases synthesis of the 4HB polypeptide in vitro.
6. The 41-1B polypeptide of claim 1 , wherein the 4HB polypeptide further comprises an amino acid substitution, addition or deletion that increases protease resistance of the 4HB polypeptide.
7. The 4HB polypeptide of claim 1 , wherein the non-naturally encoded amino acid includes a side chain functional group that reacts selectively with a linker, polymer, or biologically active molecule.
8. The 4HB polypeptide of claim 1 , wherein the non-naturally encoded amino acid comprises a carbonyl group.
9. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide comprises one or more post-translational modifications.
10. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide is linked to a linker, polymer, or biologically active molecule.
11. The 4HB polypeptide of claim 10 , wherein the 4HB polypeptide is linked to a water soluble polymer.
12. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide is linked to a multifunctional polymer, bifunctional linker, or at least one additional 4HB polypeptide.
13. The 4HB polypeptide of claim 12 , wherein the bifunctional linker or bifunctional polymer is linked to a second polypeptide.
14. The 4HB polypeptide of claim 13 , wherein the second polypeptide is a 4HB polypeptide.
15. The 4HB polypeptide of claim 11 , wherein the water soluble polymer comprises a poly (ethylene glycol) moiety.
16. The 4HB polypeptide of claim 11 , wherein said water soluble polymer is linked to a non-naturally encoded amino acid present in said 4HB polypeptide.
17. The 4HB polypeptide of claim 1 , wherein the 4HB polypeptide further comprises one or more free amide or free sulfhydryl groups.
18. The 4HB polypeptide of claim 17 , wherein the free amide or free sulfhydryl groups are present in naturally occurring amino acids.