Potential polypeptides recognized by interleukin(IL)-5 through screening phage displayed random peptide library / 中国免疫学杂志

ABSTRACT

Objective:To find related polypeptides which could bind interleukin (IL) 5 with high affinity.Methods:The recombinant human IL 5 was biotinylated with NSH LC Biotin,then biotinylated IL 5 was used to react with random peptide library displaying 7 amino acids fused on protein III of M13 Phage for three rounds biopanning.The selected clones were assayed by sandwich enzyme linked immunosorbent assay(ELISA)and competition ELISA.The positive clones with high affinity were used for automated sequencing with dye labeled dideoxynucleotides,and the amino acid sequence of polypeptide displayed on phage was deduced.Results:The enrichment was shown by ELISA after 3 rounds of biopanning.9 positive clones could bind to IL 5 with high affinity.Sequencing of the genes encoding these peptides on 9 positive clones showed some conserved epitope information such as SX 1 2 AS,ALAS.Conclusion:Potential polypeptides binding IL 5 with high affinity could be selected from phage display peptide library,SX 1 2 AS may be the motifs recognized by IL 5.