Biomolecular interaction study of hydralazine with bovine serum albumin and effect of ß-cyclodextrin on binding by fluorescence, 3D, synchronous, CD, and Raman spectroscopic methods.

Spectrofluoremetric technique was employed to study the binding behavior of hydralazine with bovine serum albumin (BSA) at different temperatures. Binding study of bovine serum albumin with hydralazine has been studied by ultraviolet-visible spectroscopy, fluorescence spectroscopy and confirmed by three-dimensional, synchronous, circular dichroism, and Raman spectroscopic methods. Effect of ß-cyclodextrin on binding was studied. The experimental results showed a static quenching mechanism in the interaction of hydralazine with bovine serum albumin. The binding constant and the number of binding sites are calculated according to Stern-Volmer equation. The thermodynamic parameters ∆H(o) , ∆G(o) , ∆S(o) at different temperatures were calculated. These indicated that the hydrogen bonding and weak van der Waals forces played an important role in the interaction. Based on the Förster's theory of non-radiation energy transfer, the binding average distance, r, between the donor (BSA) and acceptor (hydralazine) was evaluated and found to be 3.95 nm. Spectral results showed that the binding of hydralazine to BSA induced conformational changes in BSA. The effect of common ions on the binding of hydralazine to BSA was also examined. Copyright © 2016 John Wiley & Sons, Ltd.