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目的采用荧光光谱法研究有无锆离子(Zr4+)共存时槲皮素与人血清白蛋白(HSA)的相互作用。方法于10 mL的比色管中,依次加入0.20 mol/LTris-HCl缓冲溶液(pH 7.40)2.50 mL,0.10 mol/L NaCl溶液1.0 mL,一定量的HSA溶液,Zr4+溶液,槲皮素溶液,用二次蒸馏水定容至10 mL。HSA荧光激发/发射波长为281/352 nm,激发和发射光狭缝宽度为3 nm,在波长300～500 nm内记录荧光光谱。结果测得了有无锆离子存在时槲皮素-HSA结合反应的平衡常数和结合摩尔位点数分别为1.032×106L/mol、2.964×105L/mol,1.13、1.07;确定槲皮素-HSA的作用类型为静态猝灭过程。结论锆离子、槲皮素对HSA荧光均有猝灭作用,而且二者共存时对HSA荧光有协同猝灭作用,其猝灭机制为槲皮素与锆离子形成配合物后再对HSA的荧光有猝灭作用,而不是槲皮素和锆离子各自猝灭的简单累加。
Objective To investigate the interaction between quercetin and human serum albumin (HSA) in the presence or absence of zirconium ions (Zr4 +) by fluorescence spectroscopy. Methods In a colorimetric tube of 10 mL, 2.50 mL of 0.20 mol / L Tris-HCl buffer solution (pH 7.40), 1.0 mL of 0.10 mol / L NaCl solution, a certain amount of HSA solution, Zr4 + solution, quercetin solution, With double distilled water volume to 10 mL. HSA fluorescence excitation / emission wavelength of 281/352 nm, excitation and emission slit width of 3 nm, in the wavelength of 300 ~ 500 nm fluorescence spectra recorded. Results The equilibrium constants and the number of binding moles of quercetin-HSA binding reaction in the presence of zirconium ions were determined as 1.032 × 106 L / mol, 2.964 × 105 L / mol, 1.13 and 1.07, respectively. The effect of quercetin-HSA The type is static quenching process. Conclusions Both zirconium and quercetin quench the fluorescence of HSA, and synergistic quenching of HSA fluorescence occurs when both of them coexist. The quenching mechanism is the fluorescence of HSA after the formation of complex with quercetin and zirconium ion Quenching effect, rather than quenching quercetin and zirconium respectively, the simple accumulation of quenching.