Fig. 1

Cyclophilin B is a novel erythrocyte receptor for P. falciparum merozoite binding. a Parameters highlighting length, molecular weight (MW), Iso-electric point (pI), number of cysteines and grand average of hydropathicity (GRAVY) of the identified host-pathogen interacting protein partners Cyclophilin B (CypB) and PfRhopH3-C. b Bacterial two-hybrid assay between identified host-pathogen interacting partners. Streaks of the identified prey protein from the bacterial two-hybrid experiment between PfRhopH3-C and human lung cDNA library on X-gal indicator plate. All streaks are labeled to represent genes cloned in pBTnn and pTRGnn. CFP10-pTRGnn/empty pBTnn is the negative control; CFP10pTRGnn/ESAT6pBTnn is the positive control. c Liquid β-galactosidase assay to measure relative enzymatic activity of co-transformant pairs. Relative Miller’s units (M.U.) of RhopH3-CpBTqq/CYPBpTRGqq, CFP10pTRGnn/ESAT6pBTnn (positive control) and CFP10-pTRGnn/empty pBTnn (negative control) were plotted. The graph is the average of three independent assays with error bars representing the standard deviation; all values were tested for significance using a two-tailed unpaired Student’s t-test with Welch’s correction. **P < 0.01, ***P < 0.001. d Localization of CypB on the RBC surface. Human erythrocytes were incubated with primary anti-CypB monoclonal antibody (mouse) followed by secondary alexa-fluor 488 conjugated goat anti-mouse IgG antibody (1:200) and confocal microscopy. e Binding of CypB on the merozoite surface. Merozoites were incubated with 25 µM recombinant CypB for 2 h followed by incubation with primary anti-CypB monoclonal antibody (mouse). The Merozoites were stained with alexa-fluor 488 conjugated goat anti-mouse IgG antibody (1:200; green) against primary antibody followed by confocal microscopy. Scale bar = 5 µm