Spectroscopic Studies on the Interaction of Vitamin C with Bovine Serum Albumin

The mechanism of binding of vitamin C (VC) with bovine serum albumin (BSA) was investigated by spectroscopic methods under simulated physiological conditions. VC effectively quenched the intrinsic fluorescence of BSA. The binding constants K-A, and the number of binding sites, n, and corresponding thermodynamic parameters Delta G(Theta), Delta H-Theta and Delta S-Theta between VC and BSA were calculated at different temperatures. The primary binding pattern between VC and BSA was interpreted as being a hydrophobic interaction. The interaction between VC and BSA occurs through static quenching and the effect of VC on the conformation of BSA was also analyzed using synchronous fluorescence spectroscopy. The average binding distance, r, between the donor (BSA) and acceptor (VC) was determined based on Forster's theory and was found to be 3.65 nm. The effects of common ions on the binding constant of VC-BSA were also examined.