Curran T M, Ma Y, Rutherford G C, Marquis R E
Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, NY 14642-8672, USA.
Can J Microbiol. 1998 Nov;44(11):1078-85. doi: 10.1139/cjm-44-11-1078.
The arginine deiminase system in oral streptococci is highly regulated. It requires induction and is repressed by catabolites such as glucose or by aeration. A comparative study of regulation of the system in Streptococcus gordonii ATCC 10558, Streptococcus rattus FA-1, and Streptococcus sanguis NCTC 10904 showed an increase in activity of the system in S. sanguis of some 1467-fold associated with induction-depression of cells previously uninduced-repressed. The activity of the system was assayed in terms of levels of arginine deiminase, the signature enzyme of the system, in permeabilized cells. Increases in enzyme levels associated with induction-depression were less for the other two organisms, mainly because of less severe repression, especially for S. rattus FA-1, which was the least sensitive to catabolite repression or aeration. Regulation of the arginine deiminase system involving induction and catabolite repression was demonstrated also with monoorganism biofilms composed of cells of S. sanguis adherent to glass slides. Fully uninduced-repressed cells from suspension cultures or biofilms were compromised in their abilities to catabolize arginine to protect themselves against acid damage. However, it was found that the system can be rapidly turned on or turned off, although induction-depression did appear to require cell growth. Still, the system could respond rapidly to the availability of arginine to reestablish high capacity for alkali production.
口腔链球菌中的精氨酸脱亚胺酶系统受到高度调控。它需要诱导，并且会被葡萄糖等分解代谢物或通气所抑制。对戈登链球菌ATCC 10558、大鼠链球菌FA-1和血链球菌NCTC 10904中该系统调控的一项比较研究表明，血链球菌中该系统的活性增加了约1467倍，这与先前未诱导-受抑制的细胞的诱导-抑制有关。该系统的活性通过在透化细胞中检测精氨酸脱亚胺酶（该系统的标志性酶）的水平来测定。对于其他两种生物体，与诱导-抑制相关的酶水平增加较少，主要是因为抑制作用较弱，特别是对于大鼠链球菌FA-1，它对分解代谢物抑制或通气最不敏感。在由粘附在载玻片上的血链球菌细胞组成的单生物膜中也证明了涉及诱导和分解代谢物抑制的精氨酸脱亚胺酶系统的调控。来自悬浮培养物或生物膜的完全未诱导-受抑制的细胞在分解精氨酸以保护自身免受酸损伤的能力方面受到损害。然而，发现该系统可以快速开启或关闭，尽管诱导-抑制似乎确实需要细胞生长。尽管如此，该系统可以对精氨酸的可用性迅速做出反应，以重新建立高碱生产能力。
