Figure 3.

Interaction of PfRipr with Rh5 and CyRPA. (a) Recombinant Rh5 and CyRPA protein expression. Recombinant Rh5 and CyRPA proteins were expressed with WGCFS as GST-fused proteins with C-terminal His-tags. The proteins were resolved by 12.5% SDS-PAGE under reducing conditions and stained with CBB. Full-length SDS-PAGE images are presented in Supplementary Fig. S2. (b) SPR single-cycle kinetic analysis sensorgrams. Recombinant PfRipr immobilized on a sensor CM5 chip was used as the ligand while either Rh5, CyRPA, or His-GST was used as analyte. Blue dots represent the real data-generated sensorgram while the black curve indicates line of fit used to calculate kinetics parameters. All assays were performed at increasing protein concentrations of 3.13, 6.25, 12.5, 25, and 50 nM at a contact time of 120 s and dissociation time of 180 s. The last dissociation time was extended to 3000 s to accurately determine kinetic parameters (Fig. S3).