Multispectroscopic studies on the interaction of maltol, a food additive, with bovine serum albumin

• Published in: Food chemistry 2012-07, Vol.133 (2), p.264-270
• Main Authors: Zhang, Guowen, Ma, Yadi, Wang, Lin, Zhang, Yepeng, Zhou, Jia
• Format: Article
• Language: English
• Subjects: Binding site; Biological and medical sciences; Bovine serum albumin; Circular Dichroism; Fluorescence quenching; Food additives; Food Additives - chemistry; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Maltol; Milk and cheese industries. Ice creams; Protein Structure, Secondary; Pyrones - chemistry; Serum Albumin, Bovine - chemistry; Spectrometry, Fluorescence - methods; Thermodynamics
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.01.014

► Interaction of maltol and bovine serum albumin (BSA) is investigated by multispectroscopic techniques. ► Maltol can quench the fluorescence of BSA through a static quenching procedure. ► The binding of maltol to BSA is driven mainly by hydrophobic interactions. ► Subdomain IIA (Sudlow site I) of BSA is found to be the main binding site for maltol. ► The secondary structure of BSA has been changed in the presence of maltol. The interaction between maltol, a food additive, and bovine serum albumin (BSA) under simulated physiological conditions was investigated by fluorescence, UV–Vis absorption, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. The results suggested that the fluorescence quenching of BSA by maltol was a static procedure forming a maltol–BSA complex. The positive values of enthalpy change and entropy change indicated that hydrophobic interactions played a predominant role in the interaction of maltol with BSA. The competitive experiments of site markers revealed that the binding of maltol to BSA mainly took place in subdomain IIA (Sudlow site I). The binding distance between maltol and BSA was 3.01nm based on the Förster theory of non-radioactive energy transfer. Moreover, the results of UV–Vis, synchronous fluorescence, CD and FT-IR spectra demonstrated that the microenvironment and the secondary structure of BSA were changed in the presence of maltol.