FIG 4.

Ability of MAbs to inhibit binding between E2₆₆₁ or Δ123 and recombinant MBP-LEL^113–201. (A) Serial dilutions of antibody were mixed with 50 ng E2 E2₆₆₁ or Δ123 and applied to plates coated with purified dimeric MBP-LEL^113–201. Bound E2 was detected with rabbit anti-His and horseradish peroxidase-labeled goat anti-rabbit IgG. Results shown are the means ± standard deviations of data from at least 2 independent experiments. Data were normalized to the percentage of E2 binding to CD81 in the absence of MAb. Curves were fitted with one-site-specific binding with the Hill slope equation in Prism v 6.0f. (B) Binding of E2₆₆₁ proteins containing one or more variable region deletions to solid-phase MBP-LEL^113–201. The inset graph shows the capture of E2 proteins with GNA-lectin and detection with anti-His antibody and confirms that similar amounts of E2 protein were present in every well. (C) Biosensor analysis of binding of E2₆₆₁ and variants containing one or more variable region deletions to dimeric MBP-LEL^113–201. Four concentrations of each E2₆₆₁ protein were flowed over biosensor chips coated with MBP-LEL^113–201, and the curves generated with 100 μg/ml E2 protein are shown.