[Screening for the peptides blocking cholera phage VP1 transfection to host cell by phage random amino acid peptide library].

Use Vibrio cholerae El Tor Typing Phage VP1 as ligand to screen phage-display random 7 amino acid peptide library, ELISA and inactivation experiment were used to identify positive clone. The ratio of output to input was increased after three rounds of screening. Pseudo-positive was decreased stepwise. It indicated the efficient enrichment. After three rounds of screening, 312 out of 360 phage clones were positive in ELISA, 1 clone shows blocking VP1 adsorbs to Vibrio cholerae by inactivation experiment. Sequencing result indicate that amino acid sequences are p245: LeuGlnGlnLysHisLeuLeu; p40, p55: GlnLeuIleMetIleArgHis; p69, p274 IleThrProArgAsnArgSer. Getting some peptides can mimick the VP1 receptor epitopes, one peptide can block VP1 transfection to host cell, it was a clue to study receptor's structure and phage infectious mechanism to host cell.