Study on mimotopes of E.coli lipopolysaccharide 2630

Objective: To screen mimotopes of E.coli lipopolysaccharide(LPS) 2630 from c7c phage display peptide library.

Methods: The LPS mimotopes were screened from c7c phage display peptide library by using affinity chromatograph-purified polyclonal antibody against E.coli LPS 2630(L2630), and the antigenicity of selected clones was identified by ELISA.

Results: After 3 rounds of biopanning, 12 out of 20 phage clones were identified as positive clones which could bind to polyclonal anti-L2630 antibody, and 5 of these 12 clones could bind to polyclonal anti-S.typhi LPS 7261(L7261) antibody. The deduced amino acid sequence analysis showed that 8 of 12 clones had the conservative sequence: X-DGLL-XX or X-EDGLL-X.

Conclusions: The peptides displayed on these phage clones can mimic the epitopes of L2630, and 5 of these phage clones mimic the common epitopes of L2630 and L7261.