Abstract: A directed chemical conjugate of a glucagon-like peptide-2 mutant, and a use thereof are provided. The glucagon-like peptide-2 mutant is based on the human glucagon-like peptide-2 through multiple site mutations and carboxy terminus extensions. By introducing a targeted chemical modification site, the glucagon-like peptide-2 mutant has biological activities consistent with the natural human glucagon-like peptide-2, and meanwhile, the half-life period in vivo is significantly prolonged, and the administration frequency is reduced, thereby achieving the purpose of treating or preventing short intestinal syndrome, intestinal mucosa injury caused by chemotherapy medicaments or radioactive treatment factors, ulcerative enteritis, chronic enteritis and non-inflammatory bowel injury disease.

Abstract: Provided in the present disclosure is a fused protein. The fused protein comprises a plurality of target protein sequences, which are connected in series, wherein every two adjacent target protein sequences are connected by means of a linker sequence, the linker sequence is suitable for being cut into a plurality of free target proteins by means of protease, the multiple target protein sequences are not cleaved by the protease, and neither the C-terminus nor the N-terminus of the free target proteins contains additional residues.