Investigation of binding mechanisms between bovine serum albumin and flutamide using multispectral techniques and molecular dynamics simulations

Flutamide, a non-steroidal anti-androgen drug, is commonly used in the treatment of prostate cancer. To understand the interaction between flutamide and blood proteins, we investigated its binding mechanism with bovine serum albumin (BSA) using multi-spectroscopic and theoretical analysis methods. Fluorescence quenching experiments revealed that the intrinsic fluorescence of BSA was reduced by the addition of flutamide through a static quenching mechanism. The formation of the BSA-flutamide complex was further confirmed using UV–visible absorption spectroscopy. The binding site number of BSA and flutamide was close to 1, indicating a single binding site between them. Thermodynamic analyses suggested that hydrophobic interactions and hydrogen bonds were the primary driving forces behind the complex formation. Circular dichroism spectroscopy showed minor conformational changes in the secondary structure of BSA upon flutamide binding. Molecular docking revealed that flutamide binds predominantly in a hydrophobic pocket of BSA, forming stable hydrogen bonds with key residues. MD simulations demonstrated that the BSA-Flutamide complex remained stable throughout the 100 ns simulation without significant structural deviations. This comprehensive analysis provides valuable reference material for understanding the interaction between flutamide and BSA during blood transport.