Manzano C, Candau P, Gomez-Moreno C, Relimpio A M, Losada M
Mol Cell Biochem. 1976 Feb 25;10(3):161-9. doi: 10.1007/BF01731687.
The dark and light reduction of nitrate and nitrite by cell-free preparations of the blue-green alga Anacystis nidulans has been investigated. The three following methods have been successfully applied to the preparation of active particulate fractions from the alga cells: (a) shaking with glass beads, (b) lysozyme treatment and lysis of the resulting protoplasts, and (c) sonication. The two enzymes of the nitrate-reducing system-namely, nitrate reductase and nitrite reductase-are firmly bound to the isolated pigment-containing particles, and can be easily solubilized by prolonging the vibration or sonication time. Both enzymes-whether solubilized or bound to the particles-depend on reduced ferredoxin as the immediate electron donor. In its presence, the alga particles catalyze the gradual photoreduction of nitrate to nitrite and ammonia, a process that can thus be considered as one of the most simple and relevant examples of Photosynthesis. Some of the properties of nitrate reductase have been studied. Nitrate reductase as well as nitrite reductase are adaptive enzymes repressed by ammonia.
对蓝绿藻集胞藻无细胞制剂还原硝酸盐和亚硝酸盐的暗反应和光反应进行了研究。以下三种方法已成功应用于从藻类细胞制备活性颗粒级分：(a) 与玻璃珠振荡；(b) 用溶菌酶处理并裂解所得原生质体；(c) 超声处理。硝酸盐还原系统的两种酶，即硝酸盐还原酶和亚硝酸盐还原酶，牢固地结合在分离出的含色素颗粒上，通过延长振荡或超声处理时间可轻易使其溶解。这两种酶，无论是溶解状态还是结合在颗粒上，都依赖于还原型铁氧还蛋白作为直接电子供体。在其存在下，藻类颗粒催化硝酸盐逐步光还原为亚硝酸盐和氨，因此该过程可被视为光合作用最简单且最相关的例子之一。已对硝酸盐还原酶的一些特性进行了研究。硝酸盐还原酶以及亚硝酸盐还原酶都是受氨抑制的适应性酶。
