State Key Laboratory of Marine Environmental Sciences of China (Xiamen University), College of Environment and Ecology, Xiamen University, Xiamen 361102, PR China.
Key Laboratory of Estuarine Ecological Security and Environmental Health, Tan Kah Kee College, Xiamen University, Zhangzhou 363105, PR China.
Food Chem. 2018 Apr 1;244:378-385. doi: 10.1016/j.foodchem.2017.10.062. Epub 2017 Oct 12.
Heavy metal chromium (Cr) poses a severe health risk to humans via food chain contamination. In this study, the interactions of either trivalent chromium (Cr(III)) or hexavalent chromium (Cr(VI)) with catalase (CAT) were investigated via multi-spectroscopic studies and computational simulations. The fluorescence analysis showed that Cr(III) and Cr(VI) quenched the fluorescence of CAT through a dynamic and a static quenching mechanism, respectively. The binding constant of Cr(VI) with CAT was 3.44×10lmol at 298K. Other detailed binding characterizations of the Cr(VI)-CAT complex were also obtained using spectra analysis and molecular docking. Synchronous fluorescence, UV-vis and circular dichroism (CD) spectral studies showed that either Cr(III) or Cr(VI) induced conformational changes of CAT, but the degree of influence was different. The response of CAT activity to Cr(III) or Cr(VI) was found to be variable depending on their valence states and concentrations.
重金属铬（Cr）通过食物链污染对人类健康构成严重威胁。在这项研究中，通过多光谱研究和计算模拟研究了三价铬（Cr（III））和六价铬（Cr（VI））与过氧化氢酶（CAT）的相互作用。荧光分析表明，Cr（III）和 Cr（VI）分别通过动态和静态猝灭机制猝灭 CAT 的荧光。在 298K 时，Cr（VI）与 CAT 的结合常数为 3.44×10lmol。还使用光谱分析和分子对接获得了 Cr（VI）-CAT 配合物的其他详细结合特性。同步荧光、紫外可见和圆二色性（CD）光谱研究表明，无论是 Cr（III）还是 Cr（VI）都诱导 CAT 的构象变化，但影响程度不同。发现 CAT 活性对 Cr（III）或 Cr（VI）的响应因价态和浓度而异。
