高纯度烟草过氧化物酶(TOPⅠ)光谱特性研究  

Study on the Spectral Characteristics of Tobacco Peroxidase I with High Purity

作　　者：夏炳乐[1] 刘清亮[1] 徐小龙[1] 施春华[1] 李敏莉[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》2003年第2期303-306,共4页Spectroscopy and Spectral Analysis

基　　金：国家烟草专卖局科研基金(100200101041)

摘　　要：采用交换吸附脱色及柱层析新技术,成功地从烟叶中分离和纯化了一种烟草过氧化物酶同工酶(TOPI),并对其进行了一系列光谱特性研究。基质辅助激光解吸电离飞行时间质谱(WALDI-TOF-MS)测得TOPI分子量为21888.5,等电点pI为3.5;氨基酸组成分析表明TOPI为一含血红素的酸性蛋白酶。光谱学分析揭示,在402nm处有一典型的Soret带,在498和636nm处有特征吸收峰(α,β带),酸度和变性剂对TOPI在紫外可见区的特征吸收峰均产生一定的影响,TOPI的荧光光谱测定结果说明TOPⅠ分子中含有Trp残基和Tyr残基以及其自身的独特的光谱学特性。Tobacco peroxidase (TOP I ) has been purified by ammonium sulfate fractionation and column chromatography, involving ion exchange on DE-52 cellulose, gelfiltration on Sephadex G-75 and ion exchange on DEAE-sephadex A-50. The specific activity of peroxidase purified was 4 826 U/mg . It has been demonstrated by SDS-PAGE as a single band. Its molecular weight (matrix assisted laser desorption/ionization time of flight mass spectra) and isoelectric point (pI) have been determined to be 21 888.5 and 3.5 respectively. The native enzyme is one of a haemachrome-containing acidic protein and has its soret maximum at 402 nm and aand β bands at 636 nm and 498 nm, respectively. Its characteristic absorption spectra and fluorescence spectra changed in different pH and denat-urant. It has its own characteristic absorption spectra and fluorescence spectra.

关 键 词：烟草 过氧化物酶 血红素 纯化 光谱性质 

分 类 号：S572[农业科学—烟草工业] Q554.6[农业科学—作物学]