Binding investigation on the interaction between Methylene Blue (MB)/TiO₂ nanocomposites and bovine serum albumin by resonance light-scattering (RLS) technique and fluorescence spectroscopy

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• 作者：Yuesheng Li ; Yue Zhang ; Shaofa Sun ; Aiqing Zhang ; Yi Liu
• 关键词：Resonance light scattering ; Fluorescence ; MB/TiO2 nanocomposites ; Bovine serum albumin ; Interaction
• 刊名：Journal of Photochemistry and Photobiology B: Biology
• 出版年：5 November, 2013
• 年：2013
• 卷：128
• 期：Complete
• 页码：12-19
• 全文大小：1701 K

文摘

The interaction between Methylene Blue (MB)/TiO₂ nanocomposites and bovine serum albumin (BSA) was investigated by resonance light scattering (RLS), fluorescence, three-dimension spectra and UV-vis absorbance spectroscopy. Several factors which may influence the RLS intensity were also investigated before characterizing MB/TiO₂-BSA complex. It was proved that the mechanism of MB/TiO₂ nanocomposites binding to BSA was mainly a result of the formation of MB/TiO₂-BSA complex. The binding constant of MB/TiO₂-BSA is 0.762 脳 10^鈭? L mol^鈭? at 298 K. By calculating the binding constant at different temperature, the thermodynamic parameters 螖H, 螖G, and 螖S can be observed and deduced that the hydrophobic interactions played an important role to stabilize the complex. The distance r (3.73 nm) between donor (BSA) and acceptor (MB/TiO₂) was obtained according to fluorescence resonance energy transfer (FRET). The binding site for MB/TiO₂ on BSA was mainly located in sub-domain IIA. The UV-vis absorbance, circular dichroism and three dimension fluorescence have also been used to investigate the effect of MB/TiO₂ on the conformation of BSA.