In vitro study on the binding of anti-coagulant vitamin to bovine serum albumin and the influence of toxic ions and common ions on binding

The mechanism of binding of vitamin K 3 (VK 3) with bovine serum albumin (BSA) was investigated by fluorescence, absorption and circular dichroism (CD) techniques under physiological conditions. The analysis of fluorescence data indicated the presence of static quenching mechanism in the binding. Various binding parameters have been evaluated. Thermodynamic parameters, the standard enthalpy change, Δ H 0 and the standard entropy change, Δ S 0 were observed to be −164.09 kJ mol −1 and −465.08 J mol −1 K, respectively. The quantitative analysis of CD spectra confirmed the change in secondary structure of the protein upon interaction with VK 3. The binding average distance, r between the donor (BSA) and acceptor (VK 3) was determined based on the Förster's theory and it was found to be 3.3 nm. The effects of toxic ions and common ions on VK 3–BSA system were also investigated.