Elucidating the mechanism of cefpodoxime-BSA interaction via a combination of multi-spectroscopic methods and molecular docking simulations

Abstract

This research provides a comprehensive elucidation of the molecular interaction between cefpodoxime (CFP) and bovine serum albumin (BSA) through an integrated approach combining computational docking and a suite of spectroscopic methods. Initial evidence from UV-Vis absorption spectroscopy confirmed a ground-state complex formation between the drug and the protein. Subsequent fluorescence quenching studies established a static quenching mechanism, with a binding constant (Kb) of 3.99 × 10⁴ L·mol^-1 determined at 298 K, indicating moderate binding affinity. Analysis of the thermodynamic parameters, computed via the Van't Hoff equation, revealed that the binding process is both spontaneous and endothermic. The positive entropy change (ΔS°) identified hydrophobic interactions as the predominant driving force for the complex formation.The binding site was precisely localized to subdomain IIA (Site I) of BSA, a finding consistently supported by two independent lines of evidence: competitive site-marker displacement assays and molecular docking simulations. Collectively, these insights into the binding affinity, forces, and specific location are fundamental for advancing the understanding of CFP's pharmacokinetic profile. This knowledge is critical for predicting its distribution and elimination in vivo, thereby informing its safe clinical use and helping to mitigate potential adverse effects.