FLUORIDE AND THE METABOLISM OF PLAQUE BACTERIA

氟化物在减少龋齿方面的有效性已经得到了很好的证实， 研究表明，F会影响牙齿的釉质和牙本质。 菌斑的产酸特性。 我们的长期利益集中在 氟对菌斑代谢的抑制作用 微生物的 F已被证明能大量抑制糖酵解 虽然不同的菌株表现出不同的敏感性 向F. 迄今为止的研究结果并不能完全解释 F.的作用机制 我们已经表明，F抑制链球菌烯醇化酶，据推测， 降低了细胞内 磷酸烯醇丙酮酸（PEP）和三磷酸腺苷（ATP）。 这是 据信是负责减少糖运输到 细胞，并最终降低产酸速率。 它 有理由认为相对耐药的微生物 补偿性地合成升高水平的一种或两种酶 和参与糖运输的载体系统，或者能够 影响控制糖酵解的调节系统的变化。 此外，我们还证明了氟可以抑制质子的迁移， ATP酶的细胞，因此，可能有直接和深远的影响， 对细胞内pH值的影响。 有可能是 不同的微生物对F. 目前的研究资助申请提出了一个程序，以检查这些 建议，并特别概述了实验，将（a）衡量 PEP-和ATP-连接的磷酸化系统，参与糖 运输，（B）检查F对糖酵解中间产物的影响 和调节过程，和（c）研究F的抑制， 噬菌斑衍生微生物中的质子转运ATP酶复合体。 将在解密细胞中用分光光度法测定酶， NAD偶联系统。 糖酵解中间体的稳态水平将 可以用酶偶联测定或通过色谱技术测量， 按照既定程序。 有人建议，这样的实验 将提供相当多的，新的见解的基本机制， F影响微生物的新陈代谢，这很可能会导致 制定新的办法，以便更有效地提供 抗龋齿剂。

The effectiveness of fluoride in reducing caries has been well established, and it has been shown that F can affect both the tooth enamel and the acidogenic properties of plaque. Our long-term interest has centered on the inhibitory effect that F exerts on the metabolism of plaque microorganisms. F has been shown to inhibit glycolysis in a large number of streptococci although different strains exhibit different sensitivities toward F. The findings to date do not allow us to fully explain the mechanism of action of F. We have shown that F inhibits streptococcal enolases and, presumably, brings about a reduction in the intracellular concentrations of phosphoenoloyruvate (PEP) and adenosinetriphosphate (ATP). This is believed to be responsible for a reduction of sugar transport into the cells and, ultimately, the dimunition of the rate of acid production. It is reasonable to propose that microorganisms that are relatively resistant to F compensatorily synthesize elevated levels of one or both of the enzyme and carrier systems that participate in sugar transport, or are able to effect changes in the regulatory systems that control glycolysis. Furthermore, we have shown that F can inhibit the proton-translocating ATPase of the cells and may, thereby, have immediate and profound effects on the intracellular pH of the cells. It is possible that the ATPases of different microorganisms respond differently to F. The present research grant application presents a program to examine these proposals and, specifically, outlines experiments that will (a) measure the PEP- and ATP-linked phosphorylating systems that participate in sugar transport, (b) examine the effects that F has on glycolytic intermediates and regulatory processes, and (c) study the inhibition by F of the proton-translocating ATPase comlex in plaque-derived microorganisms. Enzymes will be assayed in decryptified cells with spectrophotometric, NAD-coupled systems. Steady-state levels of glycolytic intermediates will be measured with enzyme-coupled assays or by chromatographic techniques, according to established procedures. It is proposed that such experiments will provide considerable, new insights into the basic mechanisms by which F affects Microbial metabolism and it is likely that these will lead to the development of new approaches for a more effective delivery of the anti-caries agent.