Screening and Identification of Mimotopes for Lipopolysaccharide Conservative Epitope from Random Phage Display Peptide Library / 生物化学与生物物理进展

ABSTRACT

To screen and identify the mimotopes for lipopolysaccharide(LPS) epitope, a rand om phage displayed dodecapeptide library was screened with a monoclonal antibody 2B4 spe ci fically against LPS conservative epitope. The positive clones were identified by phage ELISA and competitive inhibition assay by either S.typhi T 8-61 LPS or E.coli O111B4 LPS. After three rounds of biopanning,the clones binding with 2B4 antibody were well enriched with positive rate of 80%. The bindings between 12 of positive phage clones and screening antibody were competitively inhibited by the two kinds of LPS,indicating that the positive clones have similar epitope with LPS. The positive peptide sequences were deduced from the corresponding DNA sequences. There were identical sequences among them. The seq uences were GPPQWFFSQPQL （5/12，41.7%），LPQYFWNTATTA （3/12，25%），FPQNHWNVP WAT（2/12，16.6%），HSQSFWNAPLAM and AHPWTHGYFPPL （1/12，8.3%） respectively . The results demonstrate that the peptides screened with 2B4 antibody are mimot opes for LPS conservative epitope.