| abstract |
Method for preparing a lysine PEGylated IGF-I or IGF-I variant. Said variant comprises that one or two amino acids selected from the group consisting of lysine 27, 65 and / or 68 are substituted independently of another polar amino acid, culturing a prokaryotic host cell comprising an expression vector containing a nucleic acid encoding a fusion protein comprising said IGF-I or IGF-I variant N-terminally bound to the C-terminus of a propeptide, wherein said propeptide ends C-terminally with the amino acids -Y-Pro, wherein Y is selected from the group consisting of Pro, Pro-ala, Pro -Gly, Pro-Thr, Ala-Pro, Gly-Pro, Thr-Pro, Arg-Pro or Pro-Arg-Pro, recovery and PEGylation of said fusion protein, cleavage of said PEGylated fusion proteins with IgA protease and recovery of said PEGylated IGF -I or IGF-I variant. PEGylated IGF-I or IGF-I variant is useful for the treatment of neurodegenerative disorders such as Alzheimer's disease |