NMR STUDIES OF CELLULAR METABOLISM

工作总结：由于广泛的氟化 水和一些人偶尔暴露在相当大的 更高的氟化物水平，重要的是要了解 这个元素。这项研究的动机是这个问题是否 氟化物经过任何显著的合成代谢成含氟有机物质。 可能是毒性的基础的化合物。事实上，一个这样的过程 已知：丙酮酸激酶催化氟化物的磷酸化。在……里面 为了进一步研究这一过程，我们查看了其他几个 激酶，以及在氟与核苷酸的体外反应中 镁的存在。另外两种被研究的激酶：甘油激酶 和醋酸激酶，也被发现具有氟化激酶活性， 尽管程度不及丙酮酸激酶。镁离子和 研究发现，其他二价离子对氟化钾反应均有催化作用 以及氟核苷酸的形成，例如腺苷5‘-O- 氟磷酸盐和腺苷5‘-O-(2-氟二磷酸)。尽管这些 反应可以在37℃下进行，氟化物和 大量生产这些化合物所需的二价阳离子 比生物系统中的要高出几个数量级。 因此，这些过程不会对细胞构成重大毒性。 除了这些研究外，与David教授的合作研究 Thompson关于对烷基酚的代谢和潜在毒性的研究 继续。以前对简单、不受阻碍的烷基酚的研究已经被 扩展到检查额外的氟或其他卤素的影响 取代基。就像以前的研究一样，证据已经得到了 表明代谢转化是通过形成甲基苯醌来实现的 中间体。此外，苯二酚甲醚的代谢转化 对羟基苯丙酮，一种对乙酰氨基酚的类似物，也被 证明为谷胱甘肽加合物，并用核磁共振波谱对其进行了表征。

Summary of Work: As a consequence of the widespread fluoridation of water and the occasional exposure of some populations to considerably higher fluoride levels, it is important to understand the biochemistry of this element. This study was motivated by the question of whether fluoride undergoes any significant anabolism into fluorinated organic compounds which could be a basis for toxicity. In fact, one such process is known: the pyruvate kinase catalyzed phosphorylation of fluoride. In order to investigate this process further, we looked at several other kinases, and at the in vitro reaction of fluoride with nucleotides in the presence of magnesium. Two of the other kinases studied: glycerokinase and acetate kinase, were also found to exhibit fluorokinase activity, although to a lesser extent than pyruvate kinase. Magnesium ions and other divalent ions were found to catalyze both the fluorokinase reaction as well as the formation of fluoronucleotides, e.g. adenosine 5'-O- fluorophosphate and adenosine 5'-O-(2-fluorodiphosphate). Although these reactions can proceed at 37 C, the concentrations of fluoride and divalent cations required for significant production of these compounds exceed those in biological systems by several orders of magnitude. Hence, these processes would not pose significant toxicity for the cell. In addition to these studies, collaborative studies with Prof. David Thompson on the metabolism and potential toxicity of p-alkylphenols have continued. Previous studies on simple, unhindered alkylphenols have been extended to examine the effects of additional fluorine or other halogen substituents. As in the previous studies, evidence has been derived indicating metabolic transformation via formation of quinone methide intermediates. Additionally, quinone methide metabolic transformation of 4-hydroxyphenylacetone, an analog of acetaminophen, has also been demonstrated, and a glutathione adduct characterized by NMR spectroscopy.