Velasco P J, Tischner R, Huffaker R C, Whitaker J R
Department of Food Science and Technology, University of California, Davis 95616, USA.
Plant Physiol. 1989;89(1):220-4. doi: 10.1104/pp.89.1.220.
Studies on the diurnal variations of nitrate reductase (NR) activity during the life cycle of synchronized Chlorella sorokiniana cells grown with a 7:5 light-dark cycle showed that the NADH:NR activity, as well as the NR partial activities NADH:cytochrome c reductase and reduced methyl viologen:NR, closely paralleled the appearance and disappearance of NR protein as shown by sodium dodecyl sulfate gel electrophoresis and immunoblots. Results of pulse-labeling experiments with [35S]methionine further confirmed that diurnal variations of the enzyme activities can be entirely accounted for by the concomitant synthesis and degradation of the NR protein.
对在7:5明暗循环条件下生长的同步化索氏小球藻细胞生命周期中硝酸还原酶（NR）活性的昼夜变化研究表明，NADH:NR活性以及NR部分活性NADH:细胞色素c还原酶和还原甲基紫精:NR，与十二烷基硫酸钠凝胶电泳和免疫印迹所示的NR蛋白的出现和消失密切平行。用[35S]甲硫氨酸进行脉冲标记实验的结果进一步证实，酶活性的昼夜变化完全可以由NR蛋白的同步合成和降解来解释。
