FLUORIDE AND THE METABOLISM OF PLAQUE BACTERIA

氟化物对减少龋齿的有效性已经得到了很好的证实， 研究表明，氟对牙釉质和牙周组织都有影响。 斑块的产酸特性。我们的长期利益集中在 氟对斑块代谢的抑制作用 微生物。F已被证明能大量抑制糖酵解 尽管不同的菌株表现出不同的敏感性 到目前为止的调查结果还不能完全解释 其作用机理为F。 我们已经证明F抑制链球菌烯醇化酶，并推测， 带来了细胞内浓度的降低 磷酸烯丙酮酸(PEP)和三磷酸腺苷(ATP)。这是 据信是减少糖类运输到 电池，并最终成为产酸速度的关键因素。它 合理地提出相对耐药的微生物 以F代偿合成升高的一种或两种酶 以及参与糖类运输的载体系统，或能够 影响控制糖酵解的调节系统的变化。 此外，我们还证明了F可以抑制质子转移。 细胞的ATPase，并因此可能产生直接和深远的影响 对细胞内pH的影响。这是可能的ATPase的 不同的微生物对F. 本研究资助申请提出了一项计划，以审查这些 提案，具体而言，概述将(A)测量 参与糖的PEP和ATP连接的磷酸化系统 运输，(B)检查氟对糖酵解中间体的影响 和调控过程，以及(C)研究F对 斑块来源微生物中的质子转运ATPase复合体。 酶将在解密的细胞中用分光光度法检测， NAD耦合系统。糖酵解中间产物的稳定水平将 用酶偶联分析或层析技术进行测量， 根据既定的程序。有人建议这样的实验 将为基本机制提供相当大的、新的洞察力 F会影响微生物的新陈代谢，很可能会导致 开发新的方法，以便更有效地交付 防龋剂。

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.