Dreyfuss J, Pardee A B
J Bacteriol. 1966 Jun;91(6):2275-80. doi: 10.1128/jb.91.6.2275-2280.1966.
Dreyfuss, Jacques (Princeton University, Princeton, N.J.), and Arthur B. Pardee. Regulation of sulfate transport in Salmonella typhimurium. J. Bacteriol. 91:2275-2280. 1966.-The transport of sulfate into Salmonella typhimurium is an active process. Intracellular and extracellular sulfate are in rapid equilibrium. Although the entry process requires energy, the exit of sulfate and the exchange of intracellular sulfate are relatively independent of an exogenous energy supply. When a concentrated suspension of cells is first exposed to sulfate, transport is rapid, but approximately 1 min thereafter the properties of the cells change so that net sulfate flow is outwards. This overshoot seems to depend on a high intracellular sulfate concentration and on the energy supply. Transport ability is inhibited in mutants which accumulate the high energy intermediate 3'-phosphoadenosine 5'-phosphosulfate. On the basis of these results, it is suggested that the entry of sulfate is feedback-inhibited by a high-energy compound which is formed in the course of transport. Feedback inhibition, in conjunction with the repression of sulfate transport, provides an effective means of regulating the intracellular concentration. The regulatory mechanism is highly efficient in rapidly growing cells, but can be perceived as an overshoot in dense cell suspensions.
德雷福斯，雅克（普林斯顿大学，新泽西州普林斯顿），以及亚瑟·B·帕迪。鼠伤寒沙门氏菌中硫酸盐转运的调节。《细菌学杂志》91:2275 - 2280。1966年。——硫酸盐进入鼠伤寒沙门氏菌是一个主动过程。细胞内和细胞外的硫酸盐处于快速平衡状态。尽管进入过程需要能量，但硫酸盐的排出以及细胞内硫酸盐的交换相对独立于外源能量供应。当细胞的浓缩悬液首次暴露于硫酸盐时，转运迅速，但大约1分钟后细胞的特性发生变化，以至于硫酸盐的净流动向外。这种过冲似乎取决于细胞内高浓度的硫酸盐和能量供应。在积累高能中间体3'-磷酸腺苷5'-磷酸硫酸的突变体中，转运能力受到抑制。基于这些结果，有人提出硫酸盐的进入受到在转运过程中形成的一种高能化合物的反馈抑制。反馈抑制与硫酸盐转运的阻遏相结合，提供了一种调节细胞内浓度的有效手段。这种调节机制在快速生长的细胞中效率很高，但在密集细胞悬液中可能表现为过冲。
