Crystallization and preliminary structural analysis of an antibody complex formed with PfMSP1-19, a malaria vaccine candidate

The 11 kDa C-terminal fragment of the proteolyticly matured surface antigen, PfMSP1, from Plasmodium falciparum is a promising malaria vaccine candidate. The soluble recombinant form of this naturally occurring fragment has been crystallized as a complex with the Fab of a specific murine monoclonal antibody. The crystals belong to the space group P2₁, with unit-cell parameters a = 51.8, b = 213.5,c = 60.0 Å, β =101.0°, and with Z = 4. Diffraction data have been measured to 2.9 Å resolution and a preliminary model of the complex has been determined by molecular replacement. The epitope recognised by G17.12 is located on the N-terminal EGF-like domain of the antigen.