CJCU

Chem. J. Chinese Universities ›› 2001, Vol. 22 ›› Issue (1): 26.

• Articles • Previous Articles     Next Articles

Spectroscopic Studies on the Binding of Lanthanides to the Apolactoferrin

ZHU Bing1, DU Xiu-Lian1, LI Rong-Chang1, WANG Kui1, JIN Jian2, WANG Bo-Cheng2   

  1. 1. Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China;
    2. National Key Laboratory of Nuclear Medicine, Wuxi 214063, China
  • Received:2000-04-07 Online:2001-01-24 Published:2001-01-24

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Abstract: The binding of Tb 3+ and Eu 3+ to apolactoferrin has been studied on the basis of the changes in differential UV, fluorescence and CDspectra. It was found that Tb 3+ and Eu 3+ are able to bind to two ferric binding sites and the corresponding conditional equilibrium constants for the Tb 3+ binding were determined to be lg K1=8.48±0.24, lg K2=6.72±0.18(0.10 mol/L NaCl, 0.10 mol/L Hepes, pH7.4 and 25 ℃),but Tb 3+ can not displace the ferric ions from lactoferrin. By lower Tb 3+ /Lf ratio, the conformation became more compact with tryptophane residues exposed to more hydrophobic environment. When more Tb 3+ bound to Lf, the conformation changed in other direction. Anyhow, Tb 3+ binding did not affect the secondary structure.

Key words: Lactoferrin, Apolactoferrin, Lanthanide ions

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