Department of Biology, McGill University, Montreal, Quebec, Canada H3A 1B1.
Plant Physiol. 1985 Aug;78(4):665-72. doi: 10.1104/pp.78.4.665.
An improved method is described for the isolation of membrane envelope enclosing the bacteroids (peribacteroid membrane) from soybean (Glycine max L.) root nodules. The ATPase activity of the peribacteroid membrane from infected roots is compared with that of the plasma membrane from uninfected roots. The two ATPases are similar in terms of their vanadate sensitivities, pH optima, and mineral cation requirements, and show antigenic cross-reactivity. However, the ATPase of peribacteroid membrane is more sensitive to stimulation by NH(4) (+). ATP-dependent proton translocation across the peribacteroid membrane was demonstrated in broken protoplasts of infected cells, by the use of fluorescence microscopy with acridine orange. It is suggested that acidification of the peribacteroid space by the peribacteroid membrane ATPase results in the conversion of NH(3) to NH(4) (+) in this space and thereby facilitates the removal of fixed-nitrogen from the bacteroid.
本文描述了一种改良的方法，用于从大豆（Glycine max L.）根瘤中分离包围类菌体的膜包膜（类菌体膜）。比较了感染根的类菌体膜的 ATP 酶活性与未感染根的质膜的 ATP 酶活性。两种 ATP 酶在钒酸盐敏感性、pH 最佳值和矿物质阳离子需求方面相似，并表现出抗原交叉反应性。然而，类菌体膜的 ATP 酶对 NH4+的刺激更敏感。通过使用吖啶橙的荧光显微镜，在感染细胞的破碎原生质体中证明了跨类菌体膜的 ATP 依赖性质子转运。据认为，类菌体膜 ATP 酶使类菌体空间酸化，导致该空间中 NH3转化为 NH4+，从而促进从类菌体中去除固定氮。
