FIG. 3.

Time and stage dependence of the antimalarial effect of K₄K₂₀-S4 (A) and K₄-S4(1–13)a (B). Parasites at the ring (white columns) or trophozoite (black columns) stage were exposed to either K₄K₂₀-S4 or K₄-S4(1–13)a at their respective IC₅₀s for the indicated time periods. At the end of the incubation, the peptide was washed off, and parasites returned to culture conditions with [³H]hypoxanthine. Parasite-associated radioactivity was measured after 6 h and compared to the control.