Identification of peptides targeting the surface of Plasmodium falciparum-infected erythrocytes using a phage display peptide library.

Drastic changes in the plasma membrane of Plasmodium falciparum-infected red blood cells (iRBCs) make the surface of iRBCs distinct from that of the uninfected erythrocyte. To identify small peptides that would specifically recognize the altered surface of iRBCs, we screened a phage display peptide library (PDL) on the surface of iRBCs. After the sixth panning of the PDL, eight phage clones of 18 sequenced clones had the same sequence, LVDAAAL (named P1) and specific binding of P1 to the surface of iRBCs was confirmed using phage expressing P1 peptides and synthetic P1 peptide. When P1 peptide was conjugated with a peptide having moderate hemolytic activity, the peptide conjugate inhibited the growth of intracellular parasites in a dose-dependent manner, whereas control peptides were without effect. Our results demonstrate that the P1 peptide may be a lead compound for the development of anti-malarial agents targeting the surface of iRBCs.