Application of a trityl-based radical probe for measuring superoxide
Application of a trityl-based radical probe for measuring superoxide
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DOI：
10.1016/j.freeradbiomed.2003.09.014
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发表时间：
2003-12-15
影响因子：
7.4
通讯作者：
Kuppusamy, P
中科院分区：
文献类型：
--
作者：
Rizzi, C;Samouilov, A;Kuppusamy, P
研究了三芳基甲基（三苯甲基）自由基TAMOX 063用于水溶液中超氧阴离子的电子顺磁共振（EPR）检测。TAM是顺磁性的（EPR活性），高度溶于水，并在水性介质中表现出单一的尖锐EPR峰。它在生物系统中存在的许多氧化还原剂如抗坏血酸盐和谷胱甘肽的存在下也高度稳定。TAM与超氧阴离子反应的表观二级速率常数为3.1 × 10 ~（3）M ~（-1）s ~（-1）。TAM与超氧化物的特异性反应性导致EPR信号的损失，用于检测各种化学（光/核黄素/电子/供体）、酶（黄嘌呤/黄嘌呤氧化酶）和细胞（刺激的中性粒细胞）模型系统中超氧化物的产生。在EPR线宽的变化，诱导分子氧，利用在模型系统中的氧的消耗的同时测定。研究了超氧阴离子流量和TAM浓度对超氧阴离子检测效率的影响。使用TAM检测超氧化物提供了独特的优点，即，（i）利用非常低浓度的探针，（ii）其对生物还原的稳定性，和（iii）其用于同时测定超氧化物和氧的浓度。(C)2003年爱思唯尔公司
The use of triarylmethyl (trityl) free radical, TAM OX063, for detection of superoxide in aqueous solutions by electron paramagnetic resonance (EPR) spectroscopy was investigated. TAM is paramagnetic (EPR active), highly soluble in water and exhibits a single sharp EPR peak in aqueous media. It is also highly stable in presence of many oxidoreductants such as ascorbate and glutathione that are present in the biological systems. TAM reacts with superoxide with an apparent second order rate constant of 3.1 X 10(3) M-1 s(-1). The specific reactivity of TAM with superoxide, which leads to loss of EPR signal, was utilized to detect the generation of superoxide in various chemical (light/riboflavin/electron/donor), enzymatic (xanthine/xanthine oxidase), and cellular (stimulated neutrophils) model systems. The changes in the EPR line-width, induced by molecular oxygen, were utilized in the simultaneous determination of consumption of oxygen in the model systems. The effects of flux of superoxide and concentration of TAM on the efficiency of detection of superoxide were studied. The use of TAM for detection of superoxide offers unique advantages namely, (i) the utilization of very low concentration of the probe, (ii) its stability to bioreduction, and (iii) its use in the simultaneous determination of concentrations of superoxide and oxygen. (C) 2003 Elsevier Inc.