Specific erythrocyte binding capacity and biological activity of Plasmodium falciparum erythrocyte binding ligand 1 (EBL-1)-derived peptides

Erythrocyte binding ligand 1 (EBL-1) is a member of the ebl multigene family involved in Plasmodium falciparum invasion of erythrocytes. We found that five EBL-1 high-activity binding peptides (HABPs) bound specifically to erythrocytes: 29895 (⁴¹HKKKSGELNNNKSGILRSTY⁶⁰), 29903 (²⁰¹LYECGKKIKEMKWICTDNQF²²⁰), 29923 ( ⁶⁰¹CNAILGSYADIGDIVRGLDV⁶²⁰), 29924( ⁶²¹WRDINTNKLSEKFQKIFMGGY⁶⁴⁰), and 30018 ( ²⁴⁸¹LEDIINLSKKKKKSINDTSFY²⁵⁰⁰). We also show that binding was saturable, not sialic acid-dependent, and that all peptides specifically bound to a 36-kDa protein on the erythrocyte membrane. The five HABPs inhibited in vitro merozoite invasion depending on the peptide concentration used, suggesting their possible role in the invasion process.