Expressing Redundancy among Linear-Epitope Sequence Data Based on Residue-Level Physicochemical Similarity in the Context of Antigenic Cross-Reaction

Figure 4

Reduced epitope counts (1) for peptidic sequences of uniform length varying only at a single-residue position. Each count corresponds to a set of 20 peptides representing every standard proteinogenic amino-acid residue at the variable-residue position. Functional similarity is equated with either fractional aligned-sequence identity (“□”; (3) and (4)) or the Shannon information entropy for differential epitope binding ((5) through (9)). In the latter case, counts were based on steric incompatibility only (“▽”; (7) and Figure 2), both steric incompatibility and cavity formation (“⋄”; in (8)), or steric incompatibility with both cavity formation and hydrogen bonding (“△”; (8) and (9) and Table 1).