Binding specificity assay of epitope sequence in alanine scan.

Box-whisker-plot (n = 12) of the eleven residue long consensus peptide sequence TLIKELKRLGI and its derivative TLIKELKRLAI of cj0669 after incubation with antibodies reactive to C. jejuni (green) and H. pylori (blue). Each box represents 50% of the values, while 98% fall within the whiskers. The median is represented by a horizontal line within each box and the small rectangle corresponds to the mean for each sample. For references the rfi values of the positive control, Rabbit IgG, and negative control, MBP, are indicated on the right for both antibody incubations. For the original sequence a mean value of 38000 A.U. can be observed after incubation with antibody to C. jejuni. This dropped to less than 8000 A.U. after alanine substitution. This represents a drop of roughly 80% in overall intensity. In contrast, neither original nor substituted peptide showed any significant mean values after incubation with the anti-H. pylori antibodies indicating specific binding to the peptide by the anti-Campylobacter antibody.