Ce^(3+)与牛血清白蛋白的相互作用的研究

Study on Interaction of Ce^(3+) and Bovine Serum Albumin

在模拟动物体生理pH值条件下,用荧光光谱法和紫外吸收光谱法研究了稀土离子铈[Ce3+和Ce2(CO3)3]与牛血清白蛋白(BSA)的结合反应.探讨了Ce3+和Ce2(CO3)3对BSA的荧光猝灭过程机理,并分别计算了不同温度下Ce3+和Ce2(CO3)3与BSA的结合常数(KA)和实际热力学参数(△H,△G和△S),并判断了Ce3+和Ce2(CO3)3与BSA结合的作用力类型.由于所求热力学常数都是△H<0,△S>0,由此可判断Ce3+和Ce2(CO3)3与BSA之间的作用力主要为静电引力.实验结果表明,Ce3+和Ce2(CO3)3与BSA结合形成复合物,分别为:n(Ce3+):n(BSA)=1.8:1,n[Ce2(CO3)3]:n(BSA)=2.6:1.导致BSA内源性荧光猝灭是由于分子内的非辐射能量转移而引起的静态猝灭.

In physiological condition,the binding reaction of Ce3＋ and Ce2（CO3）3 with bovine serum albumin （BSA） was studied by fluorescence and UV spectra. The fluorescent mechanism of Ce3＋ and Ce2（CO3）3 with BSA was examined,and the combination constant （KA） and thermodynamic parameters （△H,△G and △S） of Ce3＋,Ce2（CO3）3 and BSA at different temperatures calculated,and the reaction type of Ce3＋ and Ce2（CO3）3 with BSA determined. From the result of △H0,△S0,It can be judged that Ce3＋,Ce2（CO3）3 and BSA had mainly electrostatic attraction. The results showed that Ce3＋ and Ce2（CO3）3 reacted with BSA to form new compound systems under nCe3＋：nBSA=1.8：1 and nCe2（CO3）3：nBSA=2.6：1. The quenching belonged to static fluorescence quenching caused by non-radiation energy transfer.