Expression of disulphide-bridge-dependent conformational epitopes and immunogenicity of the carboxy-terminal 19 kDa domain of Plasmodium yoelii merozoite surface protein-1 in live attenuated Salmonella vaccine strains.

The 19 kDa carboxy-terminal domain of Plasmodium yoelii merozoite surface protein-1 (MSP1(19)) was expressed in Salmonella vaccine strains as a carboxy-terminal fusion to fragment C of tetanus toxin (TetC). This study demonstrates that antibodies that recognize disulphide-dependent conformational epitopes in native MSP1 react with the TetC-MSP1(19) fusion protein expressed in Salmonella. The proper folding of MSP1(19) polypeptide is dependent on both the Salmonella host strain and the protein to which the MSP1(19) polypeptide is fused.