High affinity peptides binding to LPS screened from phage display random peptide library

Objective To screen and identify peptides with high affinity to lipopolysaccharide (LPS) from phage display random peptide library. Methods Using LPS as a ligand, phage clones that bond to LPS were screened from phage display random 12-mer peptide library through 4 rounds of biopanning. After binding activity was measured by ELISA and plaque reduction testing, the phage clones presenting high affinity to LPS was selected and amplified. Their DNA were extracted for sequencing, and the coding peptide sequences were deduced from the results and analyzed by bioinformatics including homology analysis through blasting. Results After 4 rounds of effective screen, 86 eluted clones were obtained and amino acid sequences of 12 positive clones with high affinity to LPS were selected and identified. The core peptide sequence of phage clones was deduced as HWQWPHWSPPP (named P11) through comparing with the results from phage display random 7-mer peptide library, which was considered to contain the motif of the common amino acid sequence for LPS affinity. There was no patent declared based on P11 sequences retrieving from patent database. There were 908 proteins matching partly to the peptide found by homology retrieval. Conclusion Peptides with high affinity to LPS are obtained from phage display random peptide library, which provide us structural foundations on further study of direct-evolution using these peptides as primers.