用玉米根尖制备的微粒体和纯化的质膜囊泡(RV和IV),研究了硝酸还原酶(NR)的存在及特性。结果表明,NR可能是存在于质膜上的内在蛋白。它与胞质中可溶性NR在NO_3~-诱导、Triton X-100激活等方面有很大差异。质膜NR和H~+跨膜运输之间没有直接的偶联关系,但是它能抑制NADH和K_3[Fe(CN)_6]之间的电子传递。文中讨论了质膜NR参与质膜氧化还原系统的可能作用模式。 The presence and characteristics of nitrate reductase (NR) were investigated using microsomes and purified plasma membrane vesicles (RV and IV) prepared from the root tip of corn. The results show that NR may be present in the plasma membrane of the intrinsic protein. It is very different from the cytoplasmic soluble NR in the induction of NO_3 ~, Triton X-100 activation and so on. There is no direct coupling between plasma membrane NR and H ~ + transmembrane transport, but it can inhibit the electron transfer between NADH and K_3 [Fe (CN) _6]. The possible mode of action of plasma membrane NR involved in plasma membrane redox system is discussed in this paper.