Fig. 3: Epitope mapping.
From: Anti-COX-2 autoantibody is a novel biomarker of immune aplastic anemia
High resolution epitope mapping was performed to identify antigen epitopes from ten (n = 10) aCOX-2 Ab positive and from two (n = 2) autoantibody negative AA plasma samples. A Linear 15 amino acid peptides with 14 amino acid overlap covering the whole COX-2 protein were spotted on a microchip. Antibody binding to the linear peptide was detected with goat anti-human IgG (Fc) DyLight6 and LI-COR Odyssey Imaging System. Scanning values are reported as fluorescence intensities (a.u.). B Autoantibody samples from which no clear epitope could be identified using linear peptides, were subjected for conformational peptide mapping. Here all peptides were cyclized using a thioether linkage linking the amino and carboxy terminals. The peptides were spotted on a microarray as 10-mers (7 and 13-mers presented in Supplementary Fig. 4) with a peptide-peptide overlap of n-1 amino acids. Signal intensities are reported as fluorescence intensities (a.u.). C Visual summary of all epitope findings reveals a shared antigenic protein sequence that is localized between amino acids 490 and 590 in the C-terminal part of COX-2.
