XANTHINE-OXIDASE HYDROGEN-PEROXIDE GENERATES SULFUR-TRIOXIDE ANION RADICAL (SO3-BULLET-) FROM SULFITE (SO3(2-)

被引：21

作者：

SUN, XY ^{[1
]}

SHI, XL ^{[1
]}

DALAL, NS ^{[1
]}

机构：

[1] W VIRGINIA UNIV,DEPT CHEM,MORGANTOWN,WV 26506

来源：

FEBS LETTERS | 1992年 / 303卷 / 2-3期

关键词：

XANTHINE OXIDASE; ESR; SPINTRAPPING; SULFITE TOXICITY; SULFUR TRIOXIDE ANION RADICAL; FREE RADICAL;

D O I：

10.1016/0014-5793(92)80522-I

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

In the presence of hydrogen peroxide (H2O2), xanthine oxidase has been found to catalyze sulfur trioxide anion radical (SO3.-) formation from sulfite anion (SO32-). The SO3.- radical was identified by ESR (electron spin resonance) spin trapping, utilizing 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) as the spin trap. Inactivated xanthine oxidase does not catalyze SO3.- radical formation, implying a specific role for this enzyme. The initial rate of SO3.- radical formation increases linearly with xanthine oxidase concentration. Together, these observations indicate that the SO3.- generation occurs enzymatically. These results suggest a new property of xanthine oxidase and perhaps also a significant step in the mechanism of sulfite toxicity in cellular systems.

引用

页码：213 / 216

页数：4

共 36 条

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