Binding properties between curcumin and malarial tubulin: molecular-docking and ab initio fragment molecular orbital calculations

Curcumin can bind to tubulin and inhibit the formation of tubulin polymer, which contributes to the formation of microtubule. Binding sites of curcumin on the αand β-tubulin heterodimer were predicted by a molecular docking study to ascertain probable causes for the observed anti-microtubule effects of curcumin. However, the specific interactions between curcumin and the tubulins have yet to be elucidated at an electronic level. We here investigated the binding properties between curcumin and αor β-tubulin of Plasmodium falciparum, using ab initio fragment molecular orbital (FMO) calculations, in order to reveal the preferable binding sites of curcumin on these tubulins. The results were compared with those for some microtubule destabilizing drugs evaluated by the same method to confirm the efficiency of curcumin as an inhibitor to the tubulins. Our ab initio FMO calculations might provide useful information for proposing novel therapeutic agents with significant binding affinity to both the αand β-tubulins.