烟草中CuZnSODⅢ的荧光光谱及pH值和H_2O_2敏感性  

Fluorescence Spectroscopy of CuZnSOD in Tobacco and Its Sensibility to pH and H2O2

作　　者：盛良全[1] 刘少民[2] 张燕[2] 徐小龙[1] 谢永树[1] 刘清亮[1] 

机构地区：[1]中国科学技术大学化学系,安徽合肥230026 [2]中国科学技术大学食品系,安徽合肥230052

出　　处：《光谱学与光谱分析》2003年第5期888-891,共4页Spectroscopy and Spectral Analysis

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。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 rim 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.

关 键 词：烟草 CuZnSODⅢ 荧光光谱 PH值 H2O2 敏感性 铜锌超氧化物歧化酶 

分 类 号：TS411[农业科学—烟草工业] O657.34[理学—分析化学]