In this paper, the effect of Hepes buffers and pH on Fe( Ⅲ ) - H2O2 - NO2- system induced bovine serum albumin ( BSA) nitration was studied by using spectrophotometry. The result showed that BSA could be nitrated by EDTA - Fe( Ⅲ ) and Ferric Citrate in Hepes buffers. In EDTA-Fe(Ⅲ) - H2O2 - NO2- system, protein nitration was increased with the increase in pH, concentration of NaNO2 was decreased with the increase in pH, the results showed that in EDTA - Fe( Ⅲ ) - H2O2 - NO2~ system, alkaline was conducive to the conduct of protein nitration. While in Ferric Citrate - H2O2 - NO2- system, protein nitration was decreased with the increase in pH, concentration of NaNO2 was increased with the increase in pH, the results showed that in Ferric Citrate - H2O2 -N02~ system, acid was conducive to the conduct of protein nitration. In addition, further study indicated that protein nitration induced by EDTA - Fe(Ⅲ) - H2O2 - NO2- was stronger than that of Ferric Citrate - H2O2 - NO2- .%采用分光光度法研究了不同pH Hepes缓冲液中Fe(Ⅲ)-过氧化氢-亚硝酸盐催化牛血清白蛋白(BSA)发生蛋白质硝化的情况.实验结果表明:在Hepes缓冲液中,EDTA-Fe(Ⅲ)及柠檬酸铁均能够催化过氧化氢-亚硝酸盐引起BSA的硝化.在EDTA-Fe(Ⅲ)-过氧化氢-亚硝酸盐体系中,BSA的硝化程度随pH的升高而依次增强,亚硝酸盐含量随pH值的升高而降低,说明碱性环境有利于EDTA-Fe(Ⅲ)-过氧化氢-亚硝酸盐催化BSA发生蛋白质硝化；而在柠檬酸铁-过氧化氢-亚硝酸盐体系中,BSA的硝化程度随pH的升高而依次降低,亚硝酸盐含量随pH值的升高而升高,说明酸性环境有利于柠檬酸铁-过氧化氢-亚硝酸盐催化BSA发生蛋白质硝化.进一步研究表明:EDTA-Fe(Ⅲ)催化过氧化氢-亚硝酸盐发生蛋白质硝化作用强于柠檬酸铁.
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