Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (02): 470-478.doi: 10.3866/PKU.WHXB201112051

• BIOPHYSICAL CHEMISTRY • Previous Articles     Next Articles

Effects of Rare Earth Ions on the Interaction between Nano TiO2 and Bovine Serum Albumin in the Presence of Ultrasound

GAO Xiao-Ya, WEN Wen, SONG Zhi-Ying, ZHANG Ai-Ping, HAO Juan, HUANG Qian   

  1. Department of Pharmacy, Shanxi Medical University, Taiyuan 030001, P. R. China
  • Received:2011-08-24 Revised:2011-11-25 Published:2012-01-11
  • Contact: ZHANG Ai-Ping
  • Supported by:

    The project was supported by the Natural Science Foundation of Shanxi Province, China (2010011048-1) and Technology Innovation Foundation of Shanxi Medical University, China (01200806).

Abstract: The effects of rare earth ions (La3+ , Gd3+ , Yb3+ ) on the interactions between nano TiO2 and bovine serum albumin (BSA) were investigated in the presence of ultrasound. A combination of ultraviolet (UV) spectroscopy, fluorescence spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to characterize the interactions under simulated human physiological conditions. The endogenous fluorescence of BSA was quenched by nano TiO2 in different systems. The mechanism of fluorescence quenching was static quenching with non-radiative energy transfer. SDS-PAGE revealed that the structure of BSA was not obviously destroyed upon binding with nano TiO2 in different systems. Hydrogen bond and van der Waals interaction were deduced, on the basis of the thermodynamic parameters, to be the major driving forces. The binding distance of nano TiO2 to BSA and the thermodynamic parameters were changed in the presence of rare earth ions. However, the number of binding sites and the type of intermolecular force remained essentially unchanged. This indicated that the interaction between nano TiO2 and BSA was influenced by the rare earth ions, and that a lanthanide tetrad effect was observed. It is conjectured that rare earth ions participate in the nano TiO2-BSA interaction process by means of“ionic bridge”formation or“appositional substitution”.

Key words: Ultrasound, Nano TiO2, Bovine serum albumin, Rare earth ion, Interaction


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