吡罗昔康-Cu(Ⅱ)-牛血清白蛋白相互作用的荧光光谱法研究

Fluorescence Spectrum Characteristics of Complex of Piroxicam,Copper(Ⅱ) and BSA

应用荧光光谱法研究了生理条件下吡罗昔康对牛血清白蛋白,Cu(Ⅱ)对牛血清白蛋白以及Cu(Ⅱ)对吡罗昔康和牛血清白蛋白荧光光谱特性的影响.结果表明:Cu(Ⅱ)和吡罗昔康均可使牛血清白蛋白的荧光强度发生静态猝灭,并且在Cu(Ⅱ)存在下,吡罗昔康对牛血清白蛋白的荧光猝灭作用显著增强.根据荧光猝灭双倒数图计算吡罗昔康和牛血清白蛋白的结合常数为3.18×103 L/mol,结合位点数为0.75;二元配合物Cu(Ⅱ)与牛血清白蛋白之间的结合常数为1.13×103 L/mol,结合位点数为0.74.

The effects of Piroxicam（PIR）,Cu（Ⅱ） on the fluorescence spectrum characteristics of bovine serum albumin（BSA）were studied.The effect of Cu（Ⅱ） on the fluorescence spectrum characteristics of PIR-BSA complex was also investigated.The results showed that both Cu（Ⅱ） and PIR could quench the fluorescence intensity of BSA via a nonradiative energy transfer mechanism.Moreover,when Cu（Ⅱ） was present PIR could more significantly quench the fluorescence of BSA.The binding constants（K） and the binding sites（n） were calculated after analyzing fluorescence quenching data with a double-reciprocal equation.K and n between PIR and BSA were 3.18×103L/mol and 0.75 respectively in the PIR-BSA complex,while that between Cu（Ⅱ） and BSA were 1.13×103 L/mol and 0.74 respectively in the binary complex of copper（Ⅱ） and BSA.