烟草过氧化物酶Ⅰ-的紫外可见吸收光谱研究  

UV-Vis Absorption Spectral Characteristics of Tobacco PeroxidaseⅠ from Nicotiana Tabacum

作　　者：夏炳乐[1] 李敏莉[1] 刘清亮[1] 朱晓兰[1] 

机构地区：[1]中国科学技术大学化学系,安徽合肥230026

出　　处：《光谱学与光谱分析》2004年第7期830-833,共4页Spectroscopy and Spectral Analysis

基　　金：国家烟草总公司科研基金 (1 0 0 2 0 0 1 0 1 0 4 1 )资助项目

摘　　要：通过对烟草过氧化物酶Ⅰ (TOPⅠ )的紫外 可见光谱进行分析 ,证实了TOPⅠ为一含血红素的酸性蛋白酶。发现pH变小 ,TOPⅠ的在紫外 可见区的Soret带特征吸收峰出现蓝移 ;当pH变大时 ,则产生红移。变性剂脲对TOPⅠ的紫外 可见光谱的影响结果表明 ,当加入变性剂后 ,变性的TOPⅠ可能发生了去折叠的结构变化 ,使肽链充分伸展。向脱铁烟草过氧化物酶TOPⅠ加入相同量的Fe(Ⅲ ) ,Fe(Ⅱ ) ,Cu(Ⅱ ) ,Zn(Ⅱ ) ,Co(Ⅱ ) ,Ni(Ⅱ ) ,Sn(Ⅱ )金属离子后 ,发现除Fe(Ⅲ )基本不变外 ,溶液的UV Vis谱图发生变化 ,Soret带的最大特征吸收峰均发生不同程度的蓝移 ,且峰强减弱 ,α带和 β带特征吸收峰位置基本不变 ,但二者的相对峰强均略有减弱。The ultraviolet/visible spectra of TOP Ⅰ were studied. It was proved that TOP Ⅰ is an acid enzyme containing hemochrome as an agon. When the pH reduced, the Soret absorption in UV-Vis region exhibited a blue shift, when pH increased it exhibited a red shift. The result of the influence of carbamide, the denaturant, on the spectra showed that TOP Ⅰ may have a unfolded structural change in the solution, which made the peptide chain completely extend. After adding Fe(Ⅲ), Fe(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Co(Ⅱ), Ni(Ⅱ) and Sn(Ⅱ) to the apo-TOP Ⅰ, the UV-Vis spectra changed except for Fe(Ⅲ), which almost did not change at all. The strongest characteristic absorption peak of the Soret showed a blue shift to different extent and it became weak gradually. The situation of α-strip and β-strip remained unchanged while the relative strength decreased.

关 键 词：烟草 过氧化物酶Ⅰ 紫外-可见吸收光谱 蛋白质 

分 类 号：Q949.777.7[生物学—植物学]