Patent ID: 8597635

Claim:
A PEGylated interferon-α2b (IFN-α2b) of the structure as below, obtained by linking IFN-α2b with a Y-shaped branched polyethylene glycol (YPEG): wherein, P a and P b are same or different polyethylene glycol (PEG); j is an integer between 1-12; R i is H, substituted or unsubstituted C1-C12 alkyl group, substituted aryl, aralkyl, or heteroalkyl; and X 1 and X 2 are independently a linking group, wherein X 1 is (CH 2 ) n , and X 2 is selected from the group consisting of (CH 2 ) n , (CH 2 ) n OCO, (CH 2 ) n NHCO, and (CH 2 ) n CO, wherein n is an integer between 1-10, and wherein the YPEG is linked to IFN-α2b via an amido bond formed by the side chain ε-amino group of a Lys residue within IFN-α2b corresponding to position 134 in SEQ ID NO: 1.