Disruption of the CD147-RAP2 interaction by 6H8. (A) The overlaid flow cytometry assays of the protein-cell adhesion tests. The blank control (black), RAP2 binding to red blood cells (blue), and the reversal of the binding by 6H8Fab (red). The adhesion was detected by anti-HIS rabbit antibody and visualized with fluorescein isothiocyanate fluorescent secondary antibody by flow cytometer. (B) The crystal structure of the CD147D1-6H8Fab complex. (C) Detailed CD147D1-6H8Fab interface. (Ci) For the heavy chain of 6H8, the CD147 binding interface is located at a groove formed by CDR-H1, -H2, and -H3, where D1-βC′ (⁶¹VLKEDA⁶⁶) is half buried in the groove, resulting in 3 hydrogen bonds between D1-βC′ and the heavy chain. (Cii) Binding of CD147D1 to the light chain of 6H8 is weaker than that to its heavy chain, where 2 hydrogen bonds exist between the D1-βE and the light chain of 6H8; no hydrophobic interaction was observed. (D) The invasion assay of the CD147 peptide derived from the CD147-6H8 interface epitope against P falciparum 3D7 strain in vitro (n = 3). The control peptide represents the randomized sequence of the CD147 peptide. For data acquisition, parasitemia was measured by SYBR Green I staining with a flow cytometer. Values are mean ± standard error of the mean (SEM). (E) The binding kinetics of the CD147-derived peptide to RAP2 by SPR. The calculated K_D value is shown as mean ± SD. P values were calculated by using the analysis of variance test. ***P < .0001.