Figure 1.

PfGAMA and PfMSP10 interact directly. (A) Immunoprecipitation experiment using rabbit anti-PfGAMA antibody. In Western blot analysis, mouse anti-PfMSP10 antibody detected PfMSP10 as an ~80 kDa band (arrowhead). Lysate refers to parasite lysate derived from a 10⁸ trophozoite-/schizont-rich parasite pellet; α GST IP, sample immunoprecipitated with rabbit anti-His-GST antibody as a negative control; α GAMA IP, sample immunoprecipitated with anti-PfGAMA antibody. (B) Purified GST-tagged recombinant PfGAMA and PfMSP10 separated by 12.5% SDS-PAGE and stained with CBB. Arrowheads indicate molecular masses predicted from amino acid sequences. (C) SPR single-cycle kinetics analyses sensorgrams. Purified His-tagged recombinant PfGAMA was used as ligand and PfMSP10 as analyte at increasing concentrations of 0.16, 0.8, 4, 20, and 100 nM. Blue dots indicate experimental data while black lines indicate line of fit used to calculate the kinetic parameters. (D) IFA analysis of PfGAMA and PfMSP10. As labeled, free merozoites were co-stained with anti-PfGAMA antibodies, anti-PfMTIP (myosin tail interacting protein) antibodies, or anti-MSP10 antibodies, with (+) and without (–) permeabilization with 0.1% Triton X-100. Cells were co-stained with DAPI (for parasite nuclei localization). The left most panels and right most panels shows images of differential interference contrast (DIC) and merged pictures, respectively.