| Abstract: | Vinblastine (VLB) is an anticancer agent that inhibits microtubule assembly by binding with tubulin. Density functional theory (DFT) calculations are used to examine low-energy minima of the energy surface of vinblastine-tubulin complex. Thermodynamic data of the binding site of vinblastine to tubulin are extracted with the hybrid DFT (B3LYP (Becke, three-parameter, Lee–Yang–Parr)) method, and then the influence of several solvents, such as water, methanol and ethanol, and different temperatures are discussed on infrared parameters by self-consistent reaction field (SCRF = dipole) method. The effect of guanosine triphosphate (GTP) and guanosine diphosphate (GDP) nucleotides on vinblastine binding affinity to tubulin was realised in water solvent by comparing the changes of ?G (Gibbs free energy) of VLB-tubulin and VLB-tubulin bonded to GTP or GDP. The result showed that GDP and GTP increase significantly the binding affinity and the role of GDP is more important than that of GTP. |
