PfEBP-2 binds to aa 14-22 in exon 2 of GPC. (A) The amino acid sequence of GPC with the epitopes (overlined) corresponding to the monoclonal antibodies: Segment 1, 2B-41: antibody against GPC aa 16-22; Segment 2, 2B-39: antibody against GPC aa 1-6; Segment 3, 3-23: antibody against GPC aa 13-20; and Segment 4, 2B42: antibody against GPC aa 45-50. Exon 1 is represented by plain text; exon 2, bold text; exon 3, italicized text; and exon 4, plain text. The underlined amino acids represent the transmembrane domain. (B-C) mAbs against amino acid residues 13-20 and 16-22 of GPC inhibit binding of EBP-2 to red cells. Labeled supernatant proteins of P falciparum were mixed with normal RBCs preincubated with the different antibodies, followed by immunoprecipitations of the soluble extract. The bound PfEBP-2 is shown. Lane 1, antibody against GPC aa 16-22; lane 2, antibody against GPC aa 1-6; lane 3, antibody against GPC aa 13-20; lane 4, antibody against GPC aa 45-50; lane K-1, control mAb against the Kell protein; lane NMS, mouse preimmune serum; lane EBP-2, mouse anti–EBP-2-3.