Higher Plant Nitrate Reductase: Structure, Mechanism and Modification

硝酸还原酶(NR)是将土壤硝酸盐还原为亚硝酸盐的酶，是植物利用无机氮肥的关键步骤。本研究旨在阐明天然蛋白的结构和作用机制，该蛋白已通过亲和层析和单抗柱层析纯化至均一。南瓜NR基因已被克隆。将努力在合适的宿主中表达该基因，以便大量获得用于结晶研究的NR。该酶将受到有限的蛋白质分解，并对片段进行测序，以确定活性部位。研究结果将加深我们对硝态氮的作用机制的理解，并最终可能使植物更有效地利用氮肥。

Nitrate reductase (NR) is the enzyme that reduces soil nitrate to nitrite, a key step in the utilization of inorganic nitrogen fertilizer by plants. This proposal is aimed at elucidating the structure and mechanism of action of NR, which has been purified to homogeneity using affinity chromatography and monoclonal antibody columns. The NR gene from squash has been cloned. Efforts will be made to express this gene in a suitable host so that NR can be obtained in quantity for crystallization studies. The enzyme will be subjected to limited proteolysis and the fragments sequenced in order to identify the active sites. The results will enhance our understanding of how NR works, and may eventually enable plants to utilize nitrogen fertilizer more efficiently.