Patent ID: 7625996

Claim:
A fusion protein comprising insulin-like growth factor I (IGF-I) (SEQ ID NO: 1) or an IGF-I variant N-terminally linked to the C-terminus of a propeptide, said C-terminus of said propeptide comprising the amino acid sequence 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; Pro-Arg-Pro; Ala-Pro-Arg-Pro (SEQ ID NO: 12); and Pro-Ala-Pro-Arg-Pro (SEQ ID NO: 13) and said variant being a polypeptide which differs from SEQ ID NO: 1 in that one or two of the lysine residues at positions 27, 65, or 68 thereof is independently substituted by a polar amino acid selected from the group consisting of: cysteine; aspartic acid; glutamic acid; histidine; asparagine; glutamine; arginine; serine; and threonine; and the remainder of the amino acid sequence of said variant is the same as that of SEQ ID NO:1.