Figure 2: Inhibitory effects of IMB5046 on tubulin polymerization and its binding kinetics in vitro.

(a) Tubulin polymerization assay in vitro. IMB5046 inhibited tubulin polymerization, evaluated by turbidity changes at a wavelength of 340 nm. The experiment was repeated twice. Data from representative experiment are shown. (b) Electron micrographs of microtubules assembled in the presence or absence of IMB5046. Negatively stained samples. Scale bar, 500 nm. (c) Binding kinetics of IMB5046 (1.25, 2.5, 5, 10, 20, 40 μM) and colchicine (1.25, 2.5, 5, 10, 20, 40 μM) to tubulin (2,000 RU) determined by SPR technology. The experiment was repeated twice. Data from representative experiment are shown. RU, Resonance Units.