Modified human interferon-β polypeptides
The invention provides compositions and methods of identifying, modifying and producing modified target molecules, including therapeutic molecules by modification with non-natural amino acids. Certain aspects of the invention include methods of adding a chemical moiety to a target molecule, and the compositions resulting therefrom. Certain aspects of the invention also relate to kits for identifying, modifying and producing modified target molecules described herein.
1. A modified human interferon-β polypeptide consisting of the following amino acid alterations: methionine at position 1 to azidohomoalanine, serine at position 2 to glutamic acid, cysteine at position 17 to serine, methionine at position 36 to isoleucine, isoleucine at position 40 to phenylalanine, isoleucine at position 44 to leucine, methionine at position 62 to isoleucine, and methionine at position 117 to threonine.
2. The polypeptide of claim 1 , wherein said polypeptide is conjugated to a polyethylene glycol (PEG) at position 1 of the modified human interferon-β polypeptide.
3. The polypeptide of claim 2 , wherein said PEG is branched or unbranched.
4. The polypeptide of claim 3 , wherein said PEG has a molecular weight of from 1,000 Daltons to 100 kDa.
5. The polypeptide of claim 4 , wherein said PEG has a molecular weight selected from the group consisting of 2 kDa to 60 kDa; 2 kDa to 30 kDa, 5 kDa to 20 kDa; 10 kDa to 40 kDa; 10 kDa to 20 kDa.
6. The polypeptide of claim 2 , wherein said PEG is conjugated to the polypeptide through a triazole linkage, wherein said triazole linkage is formed by a [3+2] cycloaddition reaction.
7. A composition comprising the polypeptide of claim 1 , and a pharmaceutically acceptable diluent or excipient.