Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282, USA.
Chem Soc Rev. 2014 Jan 21;43(2):676-706. doi: 10.1039/c3cs60249d.
The nitrate anion is a simple, abundant and relatively stable species, yet plays a significant role in global cycling of nitrogen, global climate change, and human health. Although it has been known for quite some time that nitrate is an important species environmentally, recent studies have identified potential medical applications. In this respect the nitrate anion remains an enigmatic species that promises to offer exciting science in years to come. Many bacteria readily reduce nitrate to nitrite via nitrate reductases. Classified into three distinct types--periplasmic nitrate reductase (Nap), respiratory nitrate reductase (Nar) and assimilatory nitrate reductase (Nas), they are defined by their cellular location, operon organization and active site structure. Of these, Nap proteins are the focus of this review. Despite similarities in the catalytic and spectroscopic properties Nap from different Proteobacteria are phylogenetically distinct. This review has two major sections: in the first section, nitrate in the nitrogen cycle and human health, taxonomy of nitrate reductases, assimilatory and dissimilatory nitrate reduction, cellular locations of nitrate reductases, structural and redox chemistry are discussed. The second section focuses on the features of periplasmic nitrate reductase where the catalytic subunit of the Nap and its kinetic properties, auxiliary Nap proteins, operon structure and phylogenetic relationships are discussed.
硝酸根阴离子是一种简单、丰富且相对稳定的物质，但在全球氮循环、全球气候变化和人类健康中起着重要作用。尽管人们已经相当了解硝酸盐是一种重要的环境物质，但最近的研究已经确定了其潜在的医学应用。在这方面，硝酸根阴离子仍然是一种神秘的物质，有望在未来几年提供令人兴奋的科学发现。许多细菌很容易通过硝酸还原酶将硝酸盐还原为亚硝酸盐。根据其细胞位置、操纵子组织和活性位点结构，硝酸还原酶分为三种不同的类型：周质硝酸还原酶（Nap）、呼吸型硝酸还原酶（Nar）和同化型硝酸还原酶（Nas）。其中，Nap 蛋白是本综述的重点。尽管不同的变形菌中 Nap 在催化和光谱特性上有相似之处，但它们在系统发育上是不同的。这篇综述有两个主要部分：第一部分讨论了硝酸盐在氮循环和人类健康中的作用、硝酸盐还原酶的分类、同化和异化硝酸盐还原、硝酸盐还原酶的细胞位置、结构和氧化还原化学。第二部分重点介绍周质硝酸还原酶的特征，包括 Nap 的催化亚基及其动力学特性、辅助 Nap 蛋白、操纵子结构和系统发育关系。
