Abstract:
Background: The interactions of anticancer drugs with blood plasma constituents,
particularly with human serum albumin (HSA) have a major influence on drug pharmacology
and efficacy in overcoming the biological barriers to drug delivery and the targeting of active
drugs to their specific site of action. Aim: to examine the interaction of vinblastine with
human serum albumin (HSA) by means of various spectroscopic method (viz: UV/visible) in
combination with molecular docking techniques. Methods: HSA was purchased from Sigma
and used without further purification. Vinblastine, Tris(hydroxymethyl) aminomethane or Tris
Buffer (Sigma), were used as received. Doubly distilled water was used as the solvent
throughout the experiments. All reagents were of the best commercial grade and were used
without further purification. Human serum albumin of 1×10-3 M was prepared by dissolving
protein in Tris-HCl buffer solution at pH 7.4. Results: The results of fluorescence
measurements indicate that Vinblastine has a strong ability to quench the intrinsic
fluorescence of HSA through static quenching procedure. The binding constants (K) at
different temperatures and thermodynamic parameters, enthalpy changes (ΔH) and entropy
changes (ΔS) were calculated according to the fluorescence data. Furthermore, molecular
docking studies revealed that the, Vinblastine was located to the entrance of site I by
electrostatic and hydrophobic forces, which matched exactly with the corresponding
experimental results. Conclusion: All the experimental results and theoretical data indicated
that Vinblastine drug bound to HSA and was effectively transported and eliminated in the
body. Such findings may provide useful guidelines for further drug design
