| abstract |
The present invention relates to biotin-moiety-conjugated polypeptides and pharmaceutical compositions containing the same for oral administration, wherein the polypeptides according to the invention have excellent oral bioavailability in vivo. According to one embodiment of the present invention, a polypeptide having a cysteine inserted at the C-terminus, the inactive site of exendin-4, and a biotin moiety is selectively cysteine according to the present invention using the biotin moiety. By preparing conjugated polypeptides, it is possible to produce homogeneous materials without forming isomers and have increased reaction rates and yields. Furthermore, it is possible to selectively attach the biotin moiety to cysteines without affecting the biological activity and thus without inhibiting the biological activity of the polypeptide. |