FIGURE 7.

The effect of the LXC compounds on the polymerization of mammalian tubulin. (A–F) The polymerizing activity of the LXC compounds on porcine tubulin was assessed using a commercial Tubulin Polymerization Assay Kit. The LXC compounds at 1 × MIC were pre-incubated with tubulin on ice before the reaction was initiated by the addition of 1 mM GTP. The fluorescence was measured as a function of time at A₃₆₀ and A₄₂₀ nm excitation and emission wavelengths, respectively, at the constant temperature of 37°C. DMSO 2.5% (v/v) (brown curves) was used as vehicle control while paclitaxel (polymerization stabilizer; blue curves) and vinblastine (polymerization inhibitor; green curves) at 20 μM each were also included as controls.