An Exploratory Analysis of Linear Epitopes and Associated Antibody Complementarity-Determining Regions in the Immune Epitope Database

The Immune Epitope Database (IEDB) is a freely accessible database containing a significant part of the immune epitope assays described in relevant studies published over the last decades. Each epitope is classified as linear, discontinuous (possibly in multi-chain) or non-peptidic. In this work, we analyzed the subset of linear epitopes, including information about the antibody binding regions, the so-called complementarity-determining regions (CDRs). We found out that only a small percentage of assays contribute nonredundant linear epitopes with CDR3 chains, summing up to 485 entries. Furthermore, we explored some properties of these data, concluding that: (1) human and mouse hosts make up the vast majority of assays; (2) most epitopes range between 5 and 25 amino acids, whereas CDR light and heavy chain expected sizes are around 9--10 and 13--14 amino acids, respectively; (c) amino acid composition is far from uniform, with rare amino acids such as tryptophan being overrepresented, while more common ones such as lysine appearing underrepresented. Studies on other epitope-CDR datasets in the literature show similar conclusions.

Apoio/Financiamento da Pesquisa: SAE/UNICAMP e FAPESP