Abstract: By using Insight II/Affinity, molecular docking study on taxotere binding to αβ-tubulin was performed, and then a computational approach with B3LYP/6-31G was used to study the interactions of taxotere with αβ-tubulin. Optimum conformation 5 with binding energy of -190.53 kJ·mol-1 was obtained from ten conformations which were produced in the molecular docking process. The conformation 5 provides an interaction model for the binding of taxotere to αβ-tubulin, which shows herein both the hydrophobic and hydrogen bond interactions in the active site. The hydrophobic groups of tubulin are present in the bottomof active site, and forma hydrophobic space with the phenyl in both C13 side chain and C2—OBz group of taxotere. Six hydrogen bond interactions are found in the interaction model, which are located A and B binding sites respectively. Three hydrogen bond interactions between polarity group in C13 side chain and ASP26 and ARG369 in β-tubulin are found in the A site, and the other three hydrogen bond interactions between the polarity group in the cycle of taxotere and THR276, ARG278 and GLN282 in β-tubulin are found in B site. As a whole, hydrogen bond interactions in the upside of active site strengthen the interaction between taxotere and αβ-tubulin and prevent taxotere fromfalling off αβ-tubulin.

Key words: Taxotere, αβ-Tubulin, Molecular docking