Into the Groove: A Multitechnique Insight into the DNA–Vemurafenib Interaction

This study explores the interaction between Vemurafenib (VEM), a potent BRAF inhibitor, and calf thymus DNA (ctDNA) using a comprehensive array of biophysical and computational techniques. The primary objective is to understand the potential off-target effects of VEM on DNA, given its established role in melanoma therapy targeting the BRAF V600E mutation. The investigation employed methods such as ultraviolet–visible absorption spectroscopy, steady-state fluorescence, circular dichroism, isothermal titration calorimetry, and advanced molecular dynamics simulations. The results indicate that VEM interacts with DNA primarily through a minor groove-binding mechanism, causing minimal structural disruption to the DNA double helix. Viscosity measurements and melting temperature analyses further confirmed this non-intercalative mode of binding. Calorimetry data revealed an exothermic, thermodynamically favorable interaction between VEM and ctDNA, driven by both enthalpic and entropic factors. Finally, computer simulations identified the most probable binding site and mode of VEM within the minor groove of the nucleic acid, providing a molecular basis for the experimental findings.