Molecular spectroscopic studies on the interaction of morin with bovine serum albumin

The interaction between morin and bovine serum albumin (BSA) was studied using molecular spectroscopic approach at different temperatures under imitated physiological conditions. Quenching of intrinsic tryptophanyl fluorescence of BSA with increasing morin concentration is the actuating tool in the analysis. The obtained quenching mechanisms, binding constants, binding sites and corresponding thermodynamic parameters at different temperatures indicate that the hydrophobic interaction play a major role in the morin-BSA association. Binding affinity between morin and BSA was determined using Scatchard equation and the modified Stern–Volmer equation, and the corresponding Structure–affinity relationships of flavonoids were discussed. Site marker competitive displacement experiments demonstrated that morin binds with high affinity to site II (subdomain IIIA) of BSA. Furthermore, the circular dichroism spectral results indicated that the conformation of BSA changed in the presence of morin. In addition, the effect of some common metal ions on the binding constant between morin and BSA was examined.

► The binding mechanisms of morin to BSA at molecular lever was provided.
► The bind parameters, binding modes, binding site, and effect of metal ions have been explored.
► The structure-affinity relationships of flavonoids was undertaken to unravel.
► This study will help to design therapeutic drugs with more efficient than current ones.