Binding Characteristics and Superimposed Antioxidant Properties of Caffeine Combined with Superoxide Dismutase
Binding Characteristics and Superimposed Antioxidant Properties of Caffeine Combined with Superoxide Dismutase
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咖啡因与超氧化物歧化酶结合的结合特性及叠加抗氧化性能
DOI：
10.1021/acsomega.9b02205
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发表时间：
2019-10-22
期刊：
影响因子：
4.1
通讯作者：
Sheng, Liangquan
中科院分区：
文献类型：
--
作者：
Liu, Ruirui;Gang, Liping;Sheng, Liangquan
研究了咖啡因与铜/锌超氧化物歧化酶（SOD）结合的结合特性和叠加抗氧化特性。通过检测细胞中丙二醛 (MDA) 的浓度来研究咖啡因与 SOD 的叠加抗氧化活性，这是由高温和重金属暴露引起的。通过紫外光谱、荧光光谱和分子计算研究了SOD酶和咖啡因之间的相互作用。咖啡因（0.1 mmol/L）、SOD（0.1 mg/L）以及咖啡因（0.1 mmol/L）和SOD（0.1 mg/L）与细胞内水的MDA含量的相对量分别为0.70、0.72和0.54，表明咖啡因与SOD结合的抗氧化作用可能是叠加的。荧光光谱和分子计算结果表明，咖啡因和SOD的混合物可以通过氢键和范德华力自发形成1:1的复合物。咖啡因与 SOD 在 5 个不同温度下的结合常数 (Ka) 分别为 4.41 × 104、3.30 × 104、2.29 × 104、1.71 × 104 和 1.17 × 104 L/mol。吉布斯自由能(ΔG)的变化为-26.50、-26.21、-25.71、-25.12和-24.29 KJ/mol，分子对接计算的ΔG为-26.95 KJ/mol。实验结果与理论计算结果一致。咖啡因与SOD结合可以改变SOD的构象和微环境，但不改变SOD的活性。此外，组合可以叠加咖啡因和SOD的抗氧化活性。
The binding characteristics and superimposed antioxidant properties of caffeine combined with copper/zinc superoxide dismutase (SOD) were studied. The superimposed antioxidant activity of caffeine with SOD was investigated by detecting the concentration of malondialdehyde (MDA) present in cells, which was induced by hyperthermia and heavy metal exposure. The interactions between the SOD enzyme and caffeine were researched by ultraviolet spectrum, fluorescence spectrum, and molecular computation. The relative amounts of MDA contents of caffeine (0.1 mmol/L), SOD (0.1 mg/L), and caffeine (0.1 mmol/L) and SOD (0.1 mg/L) to water in cells were 0.70, 0.72, and 0.54, respectively, indicating that the antioxidant properties of caffeine combined with SOD may be superimposed. The fluorescence spectroscopy and molecular computation results show that the mixture of caffeine and SOD can result in the formation of a 1:1 complex through hydrogen bond and van der Waals forces spontaneously. The binding constant (Ka) of caffeine with SOD at five different temperatures are 4.41 × 104, 3.30 × 104, 2.29 × 104, 1.71 × 104, and 1.17 × 104 L/mol. The changes of Gibbs-free energy (ΔG) are −26.50, −26.21, −25.71, −25.12, and −24.29 KJ/mol and the ΔG of molecular docking calculation is −26.95 KJ/mol. The experimental results are in accordance with the results of theoretical calculations. The combination of caffeine with SOD can change the conformation and microenvironment of SOD but does not change the activity of SOD. In addition, the combination can superimpose the antioxidant activity of caffeine and SOD.