Figure 3. Oxyclozanide binds S100A4.

A: Effect of Zn⁺⁺ on direct binding of OX to amine coupled S100A4. 3.125–100 µM OX was injected (2 min at 30 µL/min) over S100A4 (density ∼2.4 kRU) in HBS-P with 1 mM Ca⁺⁺ ±20 µM Zn⁺⁺. Responses at late association phase are plotted versus OX concentration. Zn⁺⁺ specific binding was obtained by subtraction of responses with Ca⁺⁺ alone and curves fit to a 1∶1 model. B-C: Inhibition of S100A4 binding to immobilized RAGE (B) and TLR4 (C) by OX. 100 nM S100A4 was injected over RAGE or TLR4±0.4–200 µM OX in the presence of 1 mM Ca, 20 µM Zn and 1% DMSO. Binding was expressed as % inhibition of response with S100A4 in the absence of OX. IC₅₀ values (inserted) were calculated after curve fit to a sigmoidal dose-response model.