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采用光谱法及分子对接法考察了该化合物与人血清白蛋白(HSA)的相互作用。荧光光谱分析表明,DJS-NO_2对HSA的荧光有明显的猝灭作用,其机制属于静态荧光猝灭;温度为25℃和37℃时,猝灭常数分别为6.691×10~(13)mol/(L·s)和3.433×10~(13)mol/(L·s);结合常数分别为4.914×10~5mol/L和4.610×10~5mol/L,具有一个结合位点。热力学分析表明,该化合物与HSA之间的结合以疏水作用力为主;三维荧光光谱分析表明DJS-NO_2导致HSA氨基酸残基微环境和二级构象发生变化。圆二色谱分析显示二者的结合使得HSA的α-螺旋含量减少,提示HSA构象发生变化。分子模拟结果显示DJS-NO_2主要与HSA的位点I结合,且该化合物通过氢键与ALA118结合最紧密。
The interaction of this compound with human serum albumin (HSA) was investigated spectrophotometrically and by molecular docking. Fluorescence spectrum analysis showed that DJS-NO 2 quenches the fluorescence of HSA obviously, and its mechanism belongs to static fluorescence quenching. At 25 ℃ and 37 ℃, the quenching constants are 6.691 × 10 ~ (13) mol / (L · s) and 3.433 × 10 ~ (13) mol / (L · s), respectively. The binding constants were 4.914 × 10 ~ 5mol / L and 4.610 × 10 ~ 5mol / L, respectively. Thermodynamic analysis showed that the binding between HSA and HSA was hydrophobic. The three-dimensional fluorescence spectroscopy showed that the microenvironment and secondary conformation of HSA amino acid residues were changed by DJS-NO 2. Circular dichroism analysis revealed that the combination of the two reduced the α-helix content of HSA, suggesting a change in the conformation of HSA. The results of molecular modeling showed that DJS-NO2 mainly binds to site I of HSA, and the compound binds most closely with ALA118 through hydrogen bonding.