Characterization of dovitinib–human serum albumin association potential through optical spectroscopic and in silico approaches

The multitargeted receptor tyrosine kinase inhibitor, dovitinib (DTB) is reported to have a broad variety of pharmacological properties, which can be potentially useful in the treatment of various cancer entities. Association of DTB with the carrier protein, human serum albumin (HSA) was explored via experimental and in silico techniques. The reduction results of HSA fluorescence along with the hyperchromic effect in HSA's absorption signal observed with added DTB affirmed the DTB-HSA complex formation. Association of static quenching process for the complex was anticipated, while stabilization of the complex was asserted by a moderate binding affinity. The DTB–HSA complexation was expected to be maintained by hydrogen bonds, van der Waals and hydrophobic contacts. Variations in the protein (secondary and tertiary) conformations upon presence of DTB were verified from circular dichroism and Fourier transform infrared spectral results. Three-dimensional and synchronous fluorescence signals displayed variations in the microenvironmental make-up near protein fluorophores, consequent to the complex formation. Binding place of DTB, as detected by ligand displacement and molecular docking analyses, was found at Sudlow's site I in HSA. The results of the molecular dynamics simulations indicated that the DTB–HSA complex was stable.