甘氨酸-N,N-双(亚甲基磷酸)及其Eu(Ⅲ)配合物与BSA的作用机制

Mechanism of Interaction Between Glycine-N,N-Dimethyl Phosphonate and Its Europium( Ⅲ) Complex and Bovine Serum Albumin( BSA)

合成了一种含磷三足体甘氨酸-N,N-双(亚甲基磷酸)及其Eu(Ⅲ)的配合物,用~1HNMR,^(13)CNMR、红外光谱、元素分析、差热-热重及紫外光谱对其组成进行表征并推断了结构。结果表明:配体(L)与苦味酸铕(Eu(pic)_3)形成1∶1型配合物Eu(pic)_3L·3H_2O。用荧光光谱法研究了Eu(pic)_3L·3H_2O和牛血清白蛋白(BSA)在不同温度下的相互作用。发现配合物对BSA内源荧光的猝灭方式为静态猝灭;计算了不同温度下配合物与BSA间的结合常数K,结合位点n及相关热力学参数(ΔH>0,ΔS>0,ΔG<0),结果表明,二者主要靠疏水作用力结合。考察了Cu^(2+)和Fe^(3+)对配合物与BSA结合作用的影响,在Cu^(2+)和Fe^(3+)的介导下使配合物与BSA的结合能力增强。

A novel of phosphorus-containing tripod ligand glycine-N, N-dimethyl phosphonate and its europium complex were synthesized and characterized by elemental analysis, IR, NMR, DSC, and TGA. The consequence was proved that the ligand formed 1：1 complex Eu（pic） 3 L· 3H2O with europium. The interaction of Eu（pic） 3L·3H2O and bovine serum albumin（BSA） was studied by fluorescence spectrometry at different temperatures. The results indicated that the complex caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants K, the number of binding sites n, and corresponding thermodynamic parameters enthalpy change （△H 〉 0）, entropy change （△S 〉 0）, Gibbs free energy change （△G 〈 0 ）, between complex and BSA at different temperatures were calculated. The primary binding pattern between complex and BSA was interpreted as hydrophobic interaction. The effects of metal ions Cu^2＋ and Fe^3＋ on the interactions between BSA and complex were investigated and the results indicated that there was a stronger binding force between Eu（pic） 3L· 3H2O and BSA under the Cu^2＋ and Fe^3 ＋ mediated.