In vitro study on the binding of gemcitabine to bovine serum albumin

In the present study, the interaction of gemcitabine and bovine serum albumin (BSA) has been characterized by spectroscopic methods (fluorescence, UV-vis, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy) and molecular docking. Gemcitabine quenched BSA fluorescence in a static mode with binding constants of 6.61, 6.18, and 3.44 × 10⁴M⁻¹ at 290, 300, and 310 K, respectively. Meanwhile, the number of binding site was found to be approximately 1 from fluorescence titration data. The calculated thermodynamic parameters represent a spontaneous process and electrostatic force dominated binding, which was confirmed by the docking study. Furthermore, the alterations of protein secondary structure in the presence of gemcitabine were assessed by CD UV-vis and FT-IR spectroscopy. Fluorescence resonance energy transfer (FRET) analysis proved high probability of energy transfer from Trp residue to the drug molecule.