FIG 6.

Isolation and characterization of Ab289 from GP1_JUNV-immunized mouse serum. (A) Chromatogram showing the elution profile of Ab289 using SEC. OD, optical density. (Inset) SDS-PAGE analysis of Ab289 stained with Coomassie blue. (B) SPR sensorgram of GP1_JUNV as the analyte injected over immobilized Ab289 in a single-cycle kinetic experiment. The recorded sensorgram is shown in orange, and the fitted graph is shown in black. K_D was calculated by fitting a 1:1 binding model to the experimental data. A residual plot showing the quality of the fitted models is included below the sensorgram. The binding experiment was repeated twice, and a representative sensorgram is shown. (C) Neutralization IC₅₀ plot of JUNV-pseudotyped viruses by Ab289. The neutralization was tested using a 5-fold dilution series of Ab289. No Ab control was used to determine 100% infectivity. The IC₅₀ was calculated to be 11 ng/ml using a four-parameter sigmoidal function. The indicated values are averages from three independent experiments, each containing several technical replicates. Error bars show standard deviations. (D) Competition SPR experiments. GP1_JUNV was injected as the analyte at 200 nM over immobilized Ab289 either alone (blue) or in the presence of 1 μM Fab 289 (purple) or 1 μM Fab GD01 (green) as competitors.