【摘要】 采用光谱法,比较不同构象转铁蛋白(apo-Tf和holo-Tf,Tfs)与菁染料分子ETC之间的相互作用。利用荧光光谱法研究ETC与Tfs的相互作用机制,确定荧光猝灭类型。计算结合常数和结合位点,比较ETC与Tfs相互作用的亲和力;利用紫外-可见光谱分析ETC对Tfs构象的影响。结果表明ETC能静态猝灭Tfs的内源性荧光,且在生理条件下apo-Tf与ETC的结合能力更强,其结合常数K_a=5. 362×10~5,结合位点n=1. 27。此外,紫外光谱表明ETC对Tfs构象产生影响,且apo-Tf构象变化更加明显。更多还原

【Abstract】 The interaction between cyanine dye( ETC) and different conformational transferrin( apo-Tf and holoTf) was studied by spectroscopic methods. The interaction mechanism between ETC and Tfs was studied by fluorescence spectroscopy to determine the type of fluorescence quenching. The affinity of ETC to Tfs was compared by the calculation of binding constants and binding sites. Besides,the effect of ETC on the conformation of Tfs was analyzed by UV-Vis spectroscopy. The results showed that fluorescence quenching of Tfs by ETC was a static process and it had a stronger affinity between ETC and apo-Tf. The binding constant K_a was 5. 362 × 10~5 L/mol and binding site n was 1. 27. In addition,UV-Vis spectroscopy indicated that ETC binding had an effect on the micro-conformation of Tfs with a more obvious change with apo-Tf.更多还原