Caco-2 cell surface specific binding polypeptide and screening method thereof

Abstract

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.

Description

technical field [0001] The invention relates to the field of biotechnology, and relates to screening of blood vessel-specific binding peptides, in particular to a Caco-2 cell surface-specific binding polypeptide and a screening method thereof. Background technique [0002] Colorectal cancer (colorectal cancer) is one of the common malignant tumors of the digestive tract. With the continuous improvement of economic development and people's living standards, as well as changes in living environment, lifestyle and dietary structure, the incidence rate has increased rapidly in recent years. In western developed countries, such as the United States, the incidence of colorectal cancer ranks fourth, and it ranks second in the cause of death from malignant tumors, second only to the death rate of lung cancer. Among newly diagnosed patients, middle and advanced cancers account for the majority, and some patients are due to The clinical symptoms are not obvious or late detection leads...

AI Technical Summary

Problems solved by technology

The diagnosis and surgical treatment of colon cancer have made great progress, but the detection rate of early colon cancer is still low and the mortality rate is still high. The key to improving the survival rate and reducing mortality after colon cancer surgery lies in early detection, Early Diagnosis and Early Treatment

Images