烟草中硝酸还原酶激活与抑制的研究

Studies on the Activation and Inactivation of Nitrate Reductase from Nicotiana Tobaccum

以烟草硝酸还原酶 (简称NR)为研究对象 ,探讨了pH值、聚乙烯吡咯烷酮 (PVP)、NADH、KNO3等对其的激活或抑制作用 ,并对烟叶不同生长周期及硝酸钾诱导NR变化规律进行了研究。结果表明 :PVP有激活NR作用 ,NADH对酶活性有抑制 ,KNO3可加快酶促反应速度 ;NR催化反应的最适pH值为 7.0 ;烟叶经KNO3诱导后 ,NR活力约增加 1倍 ,并使酶活性的滞后期有所提前 ;烟叶在不同生长时期 。

The activation and inactivation of nitrate reductase(short for NR) from nicotiana tobaccum by pH, polyvinylpyrrolidone (short for PVP), NADH and KNO 3 were studied,and the regulations of changes in NR activity by the inducement of KNO 3 at different growing cycles was discussed.The results show that PVP activated NR, while NADH had an inactivating effect on NR activity.KNO 3 made the enzymatic reaction faster and the optimum pH value was 7.0 for the catalytic reaction. The activity of NR was doubled after KNO 3 induced tobacco. The inducement also made the late period short. The activity of NR was obviously different at different terms of tobacco.