【摘要】 考察了烟草中CuZnSODⅢ在不同pH值和H2O2加入量前后的荧光光谱。用同步荧光技术区分蛋白质分子中酪氨酸和色氨酸残基的荧光,进一步结合荧光猝灭现象和三维荧光特征,探讨发色团微环境及蛋白质分子构象行为,推断得出H2O2对荧光的猝灭属于氧化还原猝灭和双分子碰撞猝灭双重机制,及色氨酸残基对pH值和H2O2更为敏感的结论。更多还原

【Abstract】 In this paper, the fluorescence properties of CuZnSOD, purified from tobacco, were studied by fluorescence spectroscopy. In the range of pH 3-10, the fluorescence spectra were characterized by an emission peak at 340 nm when excited at 281 nm, and were sensitive to pH, the fluorescence intensity changed with pH, while Stokes shifts had no change. The effect of H2O2 on the fluorescence spectra was complicated with Stokes shift, peak type and intensity changing remarkablely. The synchronous and three-dimensional fluorescence presented that Trp residue was more sensitive to pH and H2O2 than Tyr residue. The titration experiments revealed the fluorescence quenching mechanism and molecular collision quenching mechanism of H2O2 .更多还原