| 硒对铬-牛血清白蛋白互作光谱特征的影响 |
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| 引用本文： | 刘康,胡承孝,蔡苗苗,高林,张梦娇,巴蕾,杨丹丹,王旭,赵小虎.硒对铬-牛血清白蛋白互作光谱特征的影响[J].浙江农业学报,2020,32(1):149. |
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| 作者姓名： | 刘康 胡承孝 蔡苗苗 高林 张梦娇 巴蕾 杨丹丹 王旭 赵小虎 |
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| 作者单位： | 1. 华中农业大学 资源与环境学院,微量元素研究中心,新型肥料湖北省工程实验室,湖北 武汉 430070; 2. 农业农村部农产品质量安全检测与评价重点实验室,广东 广州 510640 |
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| 基金项目： | 国家自然科学基金(41571321,31201501); 农业农村部农产品质量安全检测与评价重点实验室开放基金(NK201702); 中央高校基本科研业务费专项资金(2662018JC057,2019BC018) |
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| 摘 要： | 为明确Se(Ⅳ)是否影响Cr(Ⅵ)-蛋白质(牛血清白蛋白,BSA)互作体系,进而降低Cr(Ⅵ)对蛋白的毒性效应,联合紫外光谱和荧光光谱,从结合特征、作用力类型、结合位点等研究了Se(Ⅳ)对Cr(Ⅵ)-BSA互作光谱特征的影响。结果显示:Cr(Ⅵ)-BSA互作使得BSA紫外吸收增加、峰位红移、空间构象改变,表明Cr(Ⅵ)与BSA有明显的结合特征。Se(Ⅳ)与BSA未发生有效的结合,对BSA的构象和光谱特征均无显著影响。Cr(Ⅵ)能够猝灭BSA的特征荧光,是由于生成了不发荧光的1∶1基态配合物,猝灭方式为静态猝灭。通过范特霍夫(Van't Hoff)方程确定了焓变(△H=-53.528 kJ·mol-1)、熵变(△S=-0.110 kJ·mol-1·K-1)和吉布斯自由能变(△G<0),进而推断出二者间的作用力为氢键和范德瓦耳斯力,且Cr(Ⅵ)与BSA体系的相互作用为自发过程。BSA-Cr(Ⅵ)的结合距离是0.14 nm,结合位点为site Ⅱ。在Cr(Ⅵ)-BSA互作体系中,Se(Ⅳ)的添加并未改变由Cr(Ⅵ)作用引起的BSA构象和光谱特征改变。
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| 关 键 词： | 硒 铬 牛血清白蛋白 空间构象 光谱特征 |
| 收稿时间： | 2019-08-05 |
Effect of selenium on spectral characteristics of chromium interaction with bovine serum albumin |
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| LIU Kang,HU Chengxiao,CAI Miaomiao,GAO Lin,ZHANG Mengjiao,BA Lei,YANG Dandan,WANG Xu,ZHAO Xiaohu.Effect of selenium on spectral characteristics of chromium interaction with bovine serum albumin[J].Acta Agriculturae Zhejiangensis,2020,32(1):149. |
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| Authors: | LIU Kang HU Chengxiao CAI Miaomiao GAO Lin ZHANG Mengjiao BA Lei YANG Dandan WANG Xu ZHAO Xiaohu |
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| Institution: | 1. Hubei Provincial Engineering Laboratory for New-Type Fertilizer, Research Center of Trace Elements, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China;
2. Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China |
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| Abstract: | In order to determine whether Se(Ⅳ) affects the Cr(Ⅵ)-protein (bovine serum albumin, BSA) interaction system, and reduces the toxic effect of Cr(Ⅵ) on proteins, ultraviolet and fluorescence spectra were used to study the effect of Se(Ⅳ) on Cr(Ⅵ)-BSA interaction spectral characteristics, including binding characteristics, forces type, binding sites, etc. The results indicated that the addition of Cr(Ⅵ) increased the intensity of ultraviolet absorption peak of BSA, accompanied by red-shift and changes of spatial conformation. It could be deduced that there were some changes in the BSA conformation when Cr(Ⅵ) was bound to BSA. In addition, Se(Ⅳ) had no significant effect on the conformation and spectral characteristics of BSA. Cr(Ⅵ) resulted in fluorescence quenching of BSA, which was caused by the generation of substrates (1∶1) with no fluorescence. The binding constant of Cr(Ⅵ)-BSA was 4.568 8×103 L·mol-1 (298 K) and the quenching method belonged to static quenching. The thermodynamic parameters including enthalpy change (△H=-53.528 kJ·mol-1), entropy change (△S=-0.110 kJ·mol-1·K-1) and Gibb's free energy (△G<0) were calculated using Van't Hoff equation. These negative values showed that hydrogen binding and van der Waals forces were the main interaction forces in the binding of Cr(Ⅵ) to BSA and the stabilization of the complex. Moreover, the interaction of Cr(Ⅵ) and BSA was spontaneous. Further studies revealed that the binding distance of BSA-Cr (Ⅵ) was 0.14 nm and the binding site was site II. The addition of Se(Ⅳ) had no significant effect on the conformation and spectral characteristics of BSA in BSA-Cr(Ⅵ) interaction system. |
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| Keywords: | selenium chromium bovine serum albumin spatial conformation spectral characteristics |
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