Fluorescence Quenching Study on the Interaction of Some Schiff Base Complexes with Bovine Serum Albumin

• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2008,（1）
• 页码范围: 85-91
• 页数: 7页
• 语种: 英文

摘要

The interaction of Schiff base ligand A and its three metal complexes[A-Fe(Ⅱ), A-Cu(Ⅱ), and A-Zn(Ⅱ)] with bovine serum albumin (BSA) was investigated using a tryptophan fluorescence quenching method. The Schiff base ligand A and its three metal complexes all showed quenching of BSA fluorescence in a Tris-HCl buffer. Quenching constants were determined for quenching BSA by the Schiff base ligand A and its metal complexes in a Tris-HCl buffer (pH=7.4) at different temperatures. The experimental results show that the dynamic quenching constant (KSV) was increased with increasing temperature, whereas the association constant (K) was decreased with the in crease of temperature. The thermodynamic parameters ΔH, ΔG and ΔS at different temperatures were calculated.The ionic strength of the Tris-HCl buffer had a great influence on the wavelength of maximum emission of BSA.Under low ionic strength, the emission spectra of BSA influenced by A-Zn(Ⅱ) had a small blue shift. Compared to A-Zn(Ⅱ), the emission spectra of BSA in the presence of the Schiff base ligand A and A-Cu(Ⅱ) had no significant λem shift. At high ionic strength, the emission spectra of BSA upon addition of the Schiff base A, A-Fe(Ⅱ), and A-Zn(Ⅱ) all had a red shift, but the emission spectra of BSA had λem shift neither at low ionic strength, nor at high ionic strength in the presence of A-Cu(Ⅱ). Furthermore, the temperature did not affect the λem shift of BSA emission spectra.