Correlations between the conformations elucidated by CD spectroscopy and the antigenic properties of four peptides of the foot-and-mouth disease virus.

The conformational features of four related antigenic peptides (A, B, C and USA) from the foot-and-mouth disease virus (FMDV) (VP1; 141-160 of serotype A, subtype 12), assessed by CD, were found to correlate with the serological properties of these peptides. The CD spectra of the four peptides, obtained under cryogenic and solvent titration conditions, were consistent with three conformational components (a left-handed extended helix, an alpha-helix and a 3(10) helix) for peptides A and C and four components (a beta-turn of type II, an alpha-helix, a gamma-turn and a 3(10) helix) for peptides B and USA. The amino acid substitutions at positions 148 and 153, which distinguish the peptides, are therefore responsible for both their conformational and antigenic differences.