Spectroscopic studies on the interaction of lanthanum(III) 2-oxo-propionic acid salicyloyl hydrazone complex with bovine serum albumin

✍ Scribed by Ye-Zhong Zhang; Xiao-Xia Chen; Jie Dai; Xiao-Ping Zhang; Yan-Xia Liu; Yi Liu

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 525 KB
• Volume: 23
• Category: Article
• ISSN: 1522-7235
• DOI: 10.1002/bio.1025

✦ Synopsis

The interaction of lanthanum(III) 2-oxo-propionic acid salicyloyl hydrazone complex (La III L 2 ) with bovine serum albumin (BSA) was studied under physiological conditions. Fluorescence spectroscopy in combination with UV-vis absorption and circular dichroism (CD) spectroscopy were used to investigate the binding mechanism, binding constants and conformational changes of BSA in the presence of La III L 2 . It was found that the fluorescence quenching of BSA by La III L 2 resulted mainly from the formation of a La III L 2 -BSA complex. The enthalpy change (DH) and entropy change (DS) were found to be -41.03 kJ/ mol and -32.61 J/mol/K, respectively, which indicated that van der Waals' interactions and hydrogen bonds were the predominant intermolecular force in stabilizing the complex. The distance r between the donor (BSA) and acceptor (La III L 2 ) was found to be 4.35 nm, according to Förster theory of non-radioactive energy transfer. Moreover, the conformational changes of BSA by La III L 2 were analysed by means of synchronous fluorescence spectra, CD and three-dimensional fluorescence spectra. The experiment results confirmed some microenvironmental and conformational changes of BSA molecules in the presence of La III L 2 .