人红细胞保护蛋白对羟基自由基的清除作用

目的研究人红细胞保护蛋白 (HRPRP)在体外对羟基自由基 (·OH)的清除作用并探讨其抗氧化机制。方法可见光照射试管内N 羟基 2 硫代吡啶酮产生·OH ,用脱氧核糖作检测分子 ,分光光度法测定N 羟基 2 硫代吡啶酮随光照时间产生·OH的量。在反应体系中加入不同浓度的铜锌超氧化物歧化酶 (Cu ,Zn SOD)、HRPRP及二硫苏糖醇 (DTT)活化HRPRP ,观察它们对N 羟基 2 硫代吡啶酮产生的·OH的清除作用。结果Cu ,Zn SOD和HRPRP对·OH的清除率无显著性差异 (P >0 .0 5 ) ,DTT活化的HRPRP对·OH的清除率显著大于Cu ,Zn SOD(P <0 .0 1)及未活化HRPRP(P <0 .0 1)。结论证实HRPRP在巯基还原剂提供还原当量 ,暴露其自身活性位点时具有高效而特异的清除·OH的能力 ,提示HRPRP清除·OH可能是重要的抗氧化机制之一。

Removal of hydroxyl radicals by human red blood cell protect protein in vitro

PurposeTo study the removal of hydroxyl radicals(·OH) by human red blood cell protect protein(HRPRP) in vitro.MethodsReactions that employed N-hydroxyl-2-thiopyridone (C 5H 5NOS) to generate ·OH were run in test tubes that contained 5mmol/L C 5H 5NOS and 10 mmol/L deoxyribose in 50 mmol/L buffer at pH 8.0. All tubes were capped and settled in front of the 200-W light bulb. During this reaction, one test tube was taken away from light every 1 h. The time course of ·OH release from C 5H 5NOS was analyzed. Then Cu,Zn-SOD, HRPRP and activated HRPRP were added to analyze their effects on ·OH.ResultsOur experiments showed that the absorbance of sample treated with activated HRPRP was remarkably less than that with Cu,Zn-SOD (P<0.01) or HRPRP (P<0.01). No significant discrepancy was found between Cu,Zn-SOD and HRPRP (P>0.01). The above results show that HRPRP scavenge ·OH when activated by dithiolthreitol.ConclusionRemoval of ·OH by HRPRP is involved in its antioxidant properties.