FIGURE 9.

Inhibition of binding of NTa3 and its N- and C-terminal halves to B2 by KM91104. A, plates were coated with either TRX-NTa3 (for B2 analyte) or GST-CTB2 (for NTa3ΔT7 or NTa3T7 analytes). TRX-NTa3, TRX-NTa3ΔT7, and TRX-NTa3T7 were used at 400, 47, and 158 nm constant concentration, respectively. Analytes were bound in the presence of compound KM91104 or KM91201, 2-fold serially diluted (2.4 nm to 20 μm). A₄₅₀ ELISA absorbances were normalized to the highest value for the mean of each set of curves for comparison (n = 6, n = 4, and n = 3, in duplicate, respectively). B, values for IC₅₀ were obtained by using GraphPad Prism nonlinear regression and curve-fitting. Only values for KM91104 are shown. Unpaired two-tailed t tests show that these values are not significantly different. Curves for KM91201 were essentially nonconvergent, with lowest of range having an IC₅₀ >80 μm.