The role of pi-interactions and hydrogen bonds in fully protective synthetic malaria vaccine development.

Analysis of our Plasmodium falciparum malaria parasite peptides' H-NMR database in the search for H-bonds and π-interactions led us to correlate their presence or absence with a peptide's particular immunological behavior. It was concluded that a 26.5 ± 1.5 Å between positions 1 to 9 of the HLA-DRβ1* interacting region was necessary for proper docking of 20mer-long peptides and these MHC Class II molecules for full-protective immunity. Presence of intramolecular H-bonds or π-interactions leading to righ-handed α-helix or β-turn conformation in this peptide's region induces different immune responses or none. PPII conformation and the absence of any intramolecular interaction thus became the first feature characterising our immune protection-inducing structures as malaria vaccine candidates.