Multi-spectroscopic and molecular modeling studies of bovine serum albumin interaction with sodium acetate food additive

- SA interaction with BSA was investigated.
- The fluorescence quenching was due to the formation of the SA-BSA complex.
- Positive values of ΔH and ΔS showed that hydrophobic forces are acting forces.
- There was a decrease in UV absorption of BSA upon increasing SA concentration.
- A binding site of BSA plays the main role in binding of acetate.

Sodium acetate (SA) has been used as a highly effective protectant in food industry and the possible effect of this additive on the binding to albumin should be taken into consideration. Therefore, for the first time, the mechanism of SA interaction with bovine serum albumin (BSA) has been investigated by multi-spectroscopic and molecular modeling methods under physiological conditions. Stern-Volmer fluorescence quenching analysis showed an increase in the fluorescence intensity of BSA upon increasing the amounts of SA. The high affinity of SA to BSA was demonstrated by a binding constant value (1.09 × 103 at 310 °K). The thermodynamic parameters indicated that hydrophobic binding plays a main role in the binding of SA to Albumin. Furthermore, the results of UV-vis spectra confirmed the interaction of this additive to BSA. In addition, molecular modeling study demonstrated that A binding sites of BSA play the main role in the interaction with acetate.