Abstract:

The interaction between atorvastatin calcium (AC) and bovine serum albumin (BSA) was investigated using electrochemical techniques in conjunction with spectroscopy. Both enhancement and abatement actions of BSA on the peak current of AC were discussed in low and high BSA concentration ranges. In pH 7.17 phosphate buffer solution, AC caused an irreversible reduction peak on mercury electrode. With the addition of BSA into the AC solution, the peak current of AC changed and peak potential shifted. The results of linear-sweep voltammetry showed that the molecule of BSA came into being the hydrophobic tiny section where hydrophobic aromatic-group in AC molecule was embedded through hydrophobic interaction when the concentration of BSA was in the range from 1.0×10^-7 to 2.0×10^-6 mol·L^-1. The binding equilibrium constant and binding ratio were calculated as 1.67×10⁵ and 1:1, respectively. Furthermore, the results of UV absorption spectra showed that the UV absorption peak of BSA could red-shift slightly in the presence of AC. The interaction between AC and BSA could result in the change of conformationof BSA. Thus, α-helix structure in BSA was also decreased. The results of IR spectroscopy showed that AC could interact with sulfur-containing and nitrogen-containing groups in BSA molecular.

Key words: Atorvastatin calcium; Bovine serum albumin; Linear-sweep voltammetry; UV absorption spectroscopy; Fourier transforminfrared spectroscopy