Gerberding H, Mayer F
Institut für Mikrobiologie, Georg-August-Universität Göttingen, Bundesrepublik Deutschland.
Z Naturforsch C J Biosci. 1993 Jul-Aug;48(7-8):535-41. doi: 10.1515/znc-1993-7-801.
Bacterial enzyme systems, especially those which are involved in cell energetics, often show a common characteristic feature: their constituents (either interacting enzymes or subunits of a given enzyme complex) are physically separated. They are located in different functional entities, such as cytoplasm or periplasmic space. This kind of cellular and macromolecular organization enables the cell to establish spatially separated but neighbouring zones in which distinct conditions are created or maintained. This intrinsic imbalance is one of the keys for the process of life. As the mediator between the two compartments, the cytoplasm and the periplasmic space, the cytoplasmic membrane--itself a functional entity--not only acts as a barrier, but carries a set of functional enzyme components, thus contributing to the interaction between compartments. Examples to illustrate this concept are enzyme systems involved in anaerobic glycine metabolism, aerobic utilization of carbon monoxide, proton or sodium translocation across the membrane, and intracellular hydrogen cycling used by the cell for the generation of a proton gradient.
细菌酶系统，尤其是那些参与细胞能量代谢的酶系统，常常表现出一个共同的特征：它们的组成部分（无论是相互作用的酶还是给定酶复合物的亚基）在物理上是分开的。它们位于不同的功能实体中，如细胞质或周质空间。这种细胞和大分子组织使细胞能够建立空间上分开但相邻的区域，在这些区域中创造或维持不同的条件。这种内在的不平衡是生命过程的关键之一。作为细胞质和周质空间这两个区室之间的介质，细胞质膜本身就是一个功能实体，它不仅起到屏障的作用，还携带一组功能性酶成分，从而有助于区室之间的相互作用。说明这一概念的例子包括参与厌氧甘氨酸代谢、一氧化碳的有氧利用、质子或钠跨膜转运以及细胞用于产生质子梯度的细胞内氢循环的酶系统。
