The Application of Two-dimensional Fluorescence Correlation Spectroscopy on the Interaction Between Bovine Serum Albumin and Paeonolum in the Presence of Fe(III)

ABSTRACT

The effect of Fe³⁺ on the interaction between bovine serum albumin (BSA) and paeonolum (PAL), which was extracted from the traditional Chinese herb, Paeonia suffruticosa Andr, was investigated by UV and fluorescence spectroscopy. Two-dimensional correlation spectroscopy was applied to the analysis of fluorescence spectra. The results of spectroscopic measurements suggested that PAL had a strong ability to quench the intrinsic fluorescence of BSA through static quenching procedure in the presence of Fe(III). Thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) were calculated. The binding parameters including binding constant (K), and the distance (r) between PAL and BSA were evaluated on the basis of the theory of Föster energy transfer. Owing to the spectral resolution enhancement in 2D correlation spectroscopy, the structure change of PAL–Fe³⁺ can be observed.

KEYWORDS:

• bovine serum albumin
• Fe(III)
• fluorescence quenching
• paeonolum
• two-dimensional fluorescence correlation spectroscopy
• UV absorption spectroscopy