The invention discloses a Caco-2
cell surface specific binding polypeptide. Four polypeptide fragments are screened by
phage display of a random dodecapeptide
library, and the
amino acid sequences of the four polypeptide fragments are respectively as follows: SPSIDTRYSRLG, CVSVGMKPSPRP, SVSVGMKPSPRP and MVSMDSSPRDRL. According to the
screening method disclosed by the invention, colorectal
carcinoma Caco-2
cell binding polypeptide sequences are screened by a phage polypeptide display technology, the affinity of phage clones with colorectal
carcinoma cells is judged by
enzyme-linked immunosorbent
assay (ELISA), ten phage clones are obtained, and four polypeptide sequences are obtained by sequencing. The
consensus amino acid sequence is XXSXXXXXXXRXX;
homology analysis indicates that the polypeptide motif is likely to be the
amino acid determinant on the tumor
cell surface
receptor binding ligand
protein; by further judgment of cell
immunofluorescence, the targeting result of the phage positive clones implicates that the phage positive clones can be specifically bound with Caco-2 cells; and the colorectal
carcinoma Caco-2
cell specific polypeptide acquired by screening provides a preliminary experiment basis for early diagnosis of colorectal carcinoma, targeted delivery of antitumor drugs and development of targeted
small peptide drugs.