ESR studies on reaction of saccharide with the free radicals generated from the xanthine oxidase/hypoxanthine system containing iron

FEBS Letters

Mu, Ying¹  Shen, Jia-Cong²  Luo, Gui-min¹  Yang, Tong-shu¹  Qi, Dan-hua¹  Yan, Gang-ling¹  Zheng, Ying-guang¹ 

[1] Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, Jilin University, 125 Jiefang Road, Changchun 130023, PR China;Key Laboratory for Supramolecular Structure and Spectroscopy of Ministry of Education, Jilin University, 119 Jiefang Road, Changchun 130023, PR China

关键词: Alkyl/alkoxyl radical;    Free radical;    Xanthine oxidase/hypoxanthine system;    Saccharide;    Electron spin resonance;    Selenium containing abzyme;    MT;    mitochondria;    XO;    xanthine oxidase;    DMPO;    5;    5-dimethyl-1-pyrroline-1-oxide;    POBN;    tetra-pyridyl-1-oxide-N-t-butyl nitrone;    XO/HX;    xanthine oxidase/hypoxanthine system;    HX;    hypoxanthine;    Fe-XO/HX;    xanthine oxidase/hypoxanthine system containing iron;    Se-abzyme;    selenium containing abzyme;    DETPA;    diethylenetriaminepentaacetic acid;    EDTA;    ethylenediaminetetraacetic acid;    ESR;    electron spin resonance;    GPX;    glutathione peroxidase;    R;    alkyl or alkoxyl radical;    O2−;    superoxide anion;    OH;    hydroxyl radical;   

DOI  :  10.1016/S0014-5793(01)02226-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The free radicals generated from the iron containing system of xanthine oxidase and hypoxanthine (Fe-XO/HX) were directly detected by using spin trapping. It was found that not only superoxide anion (O₂ ⁻) and hydroxyl radical (OH), but also alkyl or alkoxyl radicals (R) were formed when saccharides such as glucose, fructose and sucrose were added into the Fe-XO/HX system. The generated amount of R was dependent on the kind and concentration of saccharides added into the Fe-XO/HX system and no R were detected in the absence of saccharides, indicating that there is an interaction between the saccharide molecules and the free radicals generated from the Fe-XO/HX system and saccharide molecules are essential for generating R in the Fe-XO/HX system. It is expected that the toxicity of R would be greater than of hydrophilic O₂ ⁻ and OH because they are liposoluble and their lives are longer and the active sites of biomolecules are closely related with lipophilic phase, thus they can damage cells more seriously than O₂ ⁻ and OH. The R generated from the saccharide containing Fe-XO/HX can be effectively scavenged by selenium containing abzyme (Se-abzyme), indicating Se-abzyme is a promising antioxidant.

【 授权许可】

Unknown