Fig. 3: Binding of 4h12 on PfCelTOS.
a Crystal structure of PfCelTOS in complex with 4h12 Fab. The PfCelTOS dimer is in black/gray ribbons; the heavy and light chains of 4h12 Fab are in magenta and pink ribbons. b Binding epitope of 4h12 on PfCelTOS. The PfCelTOS dimer is represented in black/gray ribbon, the binding interface is highlighted in magenta. c Binding affinity of 4h12 to PfCelTOS as determined by BLI. Representative sensorgram showing association and dissociation with 4h12 immobilized on biosensors. Black lines are sensorgrams for two-fold dilution series of PfCelTOS. Magenta lines are fitted curves correspond to a 1:1 model. The KD value is the mean ± s.e.m. from three biological replicates. d Full-length sequence of PfCelTOS. Helix and loop regions modeled in the structure were labeled. The binding interface residues are in magenta. e Mapping of epitope within the loop regions using ELISA. Each PfCelTOS mutant carries consecutive 3-4 residues mutated to alanine and the proteins were purified for ELISA to examine their interaction with 4h12. The graph is shown as mean ± s.d. of three biological replicates. f, g Comparison of the dimer orientations between PfCelTOS and PvCelTOS. Monomer A is represented in black ribbons. Monomer B is represented in gray surfaces, the dimer interface on monomer B is colored in wheat. The monomer B in both dimer structures is shown in the same orientation by superposition. f The dimer of PfCelTOS with the 4h12 binding epitope highlighted in magenta. g Only residues S71-E126 of the dimer of PvCelTOS which correspond to the resolved segment in the PfCelTOS structure are shown. The 7g7 binding epitope is highlighted in blue. h Sequence alignment of PvCelTOS and PfCelTOS. Helix and loop regions based on the structure of PvCelTOS are labeled. The binding interface residues of 7g7 and 4h12 are in blue and magenta, respectively; the dimer interface residues are highlighted in wheat.
