Ab Initio Study of Vinblastine-Tubulin Anticancer Complex

Vinblastine is an important anticancer agent known to diminish microtubule assembly. Ab initio calculations are applied to examine the structural properties and different energies of vinblastine-tubulin complex in different dielectric constants and temperatures. The aims of this work are discovery the best optimized structure and thermodynamic properties of vinblastine-tubulin complex and comparing the structure of the complex under in and out of in vivo conditions. Discovery dipole moment, frequency and intensity of vibration of the vinblastine-tubulin complex in different dielectric constants, finding free energy, enthalpy and entropy in different media that have been prepared in this paper could be useful in undrestanding the structural and thermodynamic properties of the complex. Results show the structure is more stable in water than the other media. The dipole moment of the structure at dielectric constant of 24.55 is larger than that in the other media. The intensity of vibration of the structure decreases by decreasing dielectric constant. Enthalpy and entropy energies have direct relationship with temperature. In vivo condition changes the structure and increases the affinity of vinblastine to tubulin. To confirm the reliability of the obtained data, the parameters were calculated by two methods, Hartree-Fock (HF) and Becke, three-parameter, Lee-Yang-Parr (B3LYP). The results indicated that the acquired data from these two methods are in good agreement.