Comprehensive Multispectroscopic and Molecular Docking Investigation of the Anticancer Drug Idarubicin-Bovine Serum...

Understanding the binding mechanism of idarubicin (IDA), a chemotherapeutic agent used in the treatment of acute myeloid leukemia (AML), with bovine serum albumin (BSA) is essential for elucidating its toxicity and pharmacodynamic and pharmacokinetic behavior and for supporting the development of novel drugs. In this study, the interaction between IDA and BSA was comprehensively investigated using spectroscopic techniques, including steady-state fluorescence, 3D fluorescence, synchronous fluorescence, competitive displacement assays, UV-Vis absorption spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy, along with dynamic light scattering (DLS) and molecular docking analysis. The interaction was confirmed by fluorescence and UV-Vis spectra, and the binding constant was determined as K_a = 1.74 × 10⁴ M^-1. Fluorescence quenching analysis indicated a predominantly static quenching mechanism, suggesting the formation of a ground-state complex. Thermodynamic results revealed that hydrogen bonding, hydrophobic interactions, and van der Waals forces play dominant roles in the binding process. Furthermore, 3D and synchronous fluorescence studies demonstrated that IDA alters the polarity of the BSA microenvironment. Molecular docking and displacement studies showed that IDA binds to all three BSA sites, with a significantly higher affinity for Site III compared to Site I and Site II. These findings provide valuable insight into the IDA-BSA interaction mechanism.