Conformation and immunogenicity of engineered repeating segment of the circumsporozoite surface protein of Plasmodium falciparum.

Peptide vaccines based on units of the immunodominant tetrapeptide repeats, Asn-Ala-Asn-Pro and Asn-Val-Asp-Pro, of the circumsporozoite surface protein of the parasite Plasmodium falciparum are presently being developed as potential malaria vaccines. The N-terminal fusion of a hydrophobic protein to units of the tetrapeptide repeat affected the immunogenicity and conformational stability of the peptide, and also induced a secondary structure in the peptide. Peptide antigenicity, as well as conformational stability, was significantly increased.