Multispectroscopic studies on the interaction of 2- tert-butylhydroquinone (TBHQ), a food additive, with bovine serum albumin

Abstract

The interaction of 2- tert-butylhydroquinone (TBHQ) and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorimetry, circular dichroism (CD) and FT-IR techniques. The experimental results indicated that the quenching mechanism of BSA by TBHQ was a static procedure. Various binding parameters were evaluated. The negative value of Δ H, positive value of Δ S and the negative value of Δ G indicated that hydrophobic and hydrogen bonding interactions play major roles in the binding of TBHQ and BSA. Based on Forster’s theory of non-radiation energy transfer, the binding distance, r, between the donor (BSA) and acceptor (TBHQ) was evaluated. The results of CD, UV–vis and FT-IR spectroscopy showed that the binding of TBHQ to BSA induced conformational changes in BSA.