Fig. 6
From: Improving the cytotoxicity of immunotoxins by reducing the affinity of the antibody in acidic pH
32A9 and 42A1 showed different antigen-binding capacities in acidic pH. Affinity analysis of 32A9 and 42A1 to purified GPC3 protein (A) and A431-GPC3 cells (B) under different pH environments, contains pH 7.4 and pH 5.0. Blue: 32A9, red: 42A1. Values represent the mean ± SD, n = 3 individual tests in (A). C Affinity analysis of 32A9 and 42A1 to purified GPC3 protein under different pH environments, contains pH 7.4, pH 6.5, pH 5.0 and pH 4.5. Blue: 32A9, red: 42A1. n = 1 individual test. D Binding activity of 32A9 and 42A1 to A431-GPC3 cells under different pH environments, contains pH 7.4, pH 6.5 and pH 5.0. Blue: 32A9, red: 42A1. Gray: secondary antibody only as a negative control. E Alignment of 32A9 and 42A1 CDR sequence. F Surface charge distribution of scFv antibodies. The structure model of 32A9 and 42A1 scFv generated by Phyre2. Surface charge is calculated and visualized by PyMOL. Blue: Positive charge, Red: Negative charge