褪黑素和芦丁抑制蛋白质硝基化的比较研究

以牛血清白蛋白为硝化底物、过氧亚硝酸为硝化试剂,研究了褪黑素和芦丁对蛋白质硝基化的抑制作用.通过对硝基化反应各种影响因素的探讨,发现在37℃,pH 7.2,反应时间90 min以及过氧亚硝酸浓度为6.0×10~(-4)mol/L时,硝基化反应进行最完全.实验分别在硝基化反应进行前、进行中以及反应后,在硝基化反应体系中引入不同浓度的抑制剂褪黑素和芦丁.结果显示,在硝基化反应发生前加入抑制剂,抑制硝基化反应的效果最为明显;当褪黑素和芦丁的终浓度为5.0×10~(-5) mol/L时,抑制率分别达到80.7%和52.4%;若继续增加褪黑素,抑制率几乎不再变化,继续增加芦丁,抑制率小幅上升后开始呈下降趋势.总的来说,褪黑素抑制蛋白质硝基化的效果明显好于同浓度的芦丁.

Comparative Studies on Melatonin and Rutin Inhibiting Protein Nitration

Using BSA (bovine serum albumin) as nitrated substrate and peroxynitrite as nitrification reagent,the inhibition effects of melatonin and rutin on protein nitration were investigated.It was observed that the optimum conditions for complete nitration were pH 7.2,temperature 37 ℃,90 min for reaction time and peroxynitrite concentration of 6.0 × 10~(-4)mol/L.Under these conditions,various concentrations of melatonin and rutin were used for test at different time point.The data displayed that addition of melatonin or rutin before the process can efficiently retard the reaction,and 5.0× 10~(-5)mol/L melatonin or rutin led to 80.7% and 52.4% reduction of maximum nitration respectively.The rate of inhibition was stable with increasing concentration of melatonin,but decreased after slight increase with more rutin.On the whole,melatonin had the better effect on nitration inhibition than rutin with same concentration.