NMR STUDIES OF CELLULAR METABOLISM

细胞代谢的核磁共振研究

• 批准号: 6162235
• 负责人: R E LONDON
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6162235
• 关键词: acetone; cellular respiration; cytochrome P450; enzyme activity; fluorine; glutathione; glycerol kinase; halogenation; intracellular; laboratory rat; nonsteroidal antiinflammatory agent; nuclear magnetic resonance spectroscopy; phenols; pyruvate kinase; quinones

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.

工作总结：由于广泛的氟化， 水和一些人口偶尔接触到相当多的 更高的氟化物水平，重要的是要了解的生物化学 这个元素。 这项研究的动机是， 氟化物在氟化有机物中发生任何显著的反硝化作用， 这些化合物可能是毒性的基础。 事实上， 已知的是：丙酮酸激酶催化磷酸化的氟化物。 在 为了进一步研究这个过程，我们研究了其他几个 激酶，并在体外反应的氟化物与核苷酸在 镁的存在。 研究的其他两种激酶：甘油激酶 和乙酸激酶，也被发现表现出氟激酶活性， 尽管程度低于丙酮酸激酶。 镁离子和 发现其它二价离子催化氟激酶反应 以及荧光素的形成，例如腺苷5 '-O- 氟磷酸和腺苷5 ′-O-（2-氟二磷酸）。 虽然这些 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 比生物系统中的高出几个数量级。 因此，这些过程不会对细胞造成显著毒性。 除了这些研究，与大卫教授的合作研究 汤普森对对烷基酚的代谢和潜在毒性的研究， 持续期间内的 以前对简单的、无阻碍的烷基酚的研究是 扩展到检查额外的氟或其他卤素的影响 取代基。 与之前的研究一样， 表明通过形成醌甲基化物的代谢转化 中间体的 此外，醌甲基化物的代谢转化 对乙酰氨基酚的类似物4-羟基苯基丙酮也已被 证明，和谷胱甘肽加合物，其特征在于通过NMR光谱。