Figure 5.

Inhibition of erythrocyte binding by DBL domains with peptide HPEP35. (A–D) Erythrocyte-binding assays were performed by using radio-labeled culture supernatants containing P. vivax region II (V), P. knowlesi β region II (Kβ), and chimeric domain CH4 with Duffy-positive (POS) human erythrocytes (RBCs) or rhesus RBCs in the presence of HPEP35, a 35-aa peptide derived from the sequence of the P. vivax-binding site on the human Duffy antigen. Binding at each HPEP35 concentration is expressed as a percentage of binding in the absence of HPEP35.