美洛昔康-Cu(Ⅱ)-牛血清白蛋白三元配合物的荧光光谱法研究

Study on the ternary complex of MLX,Copper (Ⅱ) and BSA by fluorometry

应用荧光光谱法研究了生理条件下美洛昔康对牛血清白蛋白,Cu(Ⅱ)对牛血清白蛋白以及Cu(Ⅱ)对美洛昔康和牛血清白蛋白荧光光谱特性的影响。结果表明:Cu(Ⅱ)和美洛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,美洛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美洛昔康和牛血清白蛋白的结合常数为1.91×105,结合位点数为0.95;Cu(Ⅱ)与牛血清白蛋白之间的结合常数为1.70×104,结合位点数为0.78。

The influences of meloxicam （MLX） on the fluorescence of bovine serum albumin （BSA）, copper（ II ） on that of bovine serum albumin, and copper （ II ） on that of meloxicam and bovine serum albumin were studied under the imitated physiological conditions. It was shown that both Meloxicam and copper（ II ） have powerful abilities to quench the BSA fluorescence via a nonradiative energy transfer mechanism. But the fluorescence quenching action of meloxicam on BSA was much stronger in the presence of copper（II）. The fluorescence quenching data were analyzed according to double-reciprocal equation, and the binding constant （K） and the binding site （n） were obtained. In the binarycomplex system of MLX and BSA, K is 1.91 × 10^5 and n is 0.95, while in the binary complex system of copper（ II ） and BSA, K is 1.70× 10^4 and n is 0.78.