MOLECULAR PROBES OF THE MECHANISM OF CYTOCHROME P450

该计划的中心主题涉及的机制的研究， 细胞色素P450酶和一氧化氮合酶的作用。的 主要的方法是合成和表征反应性 铁卟啉物种被认为是中间体， 催化循环，并涉及这些物种的相互转化 对这些蛋白质的分子理解。细胞色素P450是 参与药物解毒和激素的中心蛋白质 代谢，而一氧化氮和过氧亚硝酸盐。合成 金属卟啉可以用作探针来干预这些 以诊断的方式。因此，这些药剂可能被证明是 重要的工具来阐述超氧化物的生物学， 过氧亚硝酸盐和NO。这些相同的金属卟啉已经显示出令人印象深刻的 在动物中的活性表明其作为药物的应用 剂.我们的努力旨在提供一个基础的机械和 可以应用于体外模型、细胞 培养研究和特定疾病状态的整体动物模型， 如缺血再灌注、败血症和自身免疫性疾病。实验 目的是确定形成了什么反应中间体， 他们的生物目标可能是什么这些意愿的阐述 这些方法将有助于设计用于该化合物的金属络合物。 过氧亚硝酸盐和这些其它物质的催化分解。的 一氧化氮合酶的研究旨在阐明 NOS的机制，并寻找新的氧化过程，可能有助于 随着NOS抑制剂的合理开发。过氧铁（III） 卟啉物质现在在水溶液中容易获得， 环境温度快速动力学技术已经发展到 研究这些物种的反应性。一个核心问题是如何 调节这些络合物在亲核和亲核之间的化学性质， 亲电途径，这是必不可少的了解各种 P450介导的过程。合成和半合成磷脂 组件用于建模和理解更大规模的事件， P450和NOS的作用，并探测膜的通透性， 活性氧两亲性膜结合 金属卟啉对pH值非常敏感。这是一种 前所未有的观察，可能会立即应用于 金属药物的设计

The central theme of this program involves studies of the mechanisms of action of cytochrome P450 enzymes and nitric oxide synthase. The principal approach is the synthesis and characterization of reactive iron porphyrin species that are thought to be intermediates in the catalytic cycles and to relate the interconversions of these species toward a molecular understanding of these proteins. Cytochrome P450 is the central protein involved in drug detoxification and hormone metabolism while nitric oxide and peroxynitrite. Synthetic metalloporphyrins can be employed as probes to intervene in these processes in diagnostic ways. Thus, these agents may prove to be significant tools for elaborating the biology of superoxide, peroxynitrite and NO. These same metalloporphyrins have shown impressive activity in animals suggesting their application as pharmaceutical agents. Our effort seeks to provide a foundation of mechanistic and kinetic information which can be applied to in vitro models, cell culture studies and whole animal models of specific disease states such as ischemia-reperfusion, sepsis and autoimmune diseases. Experiments are aimed at determining what reactive intermediates are formed and what their biological targets are likely to be. The elaboration of these will processes will facilitate the design of metal complexes for the catalytic decomposition of peroxynitrite and these other species. The studies of nitric oxide synthase aim to illuminate the range of mechanisms of NOS and to seek out new oxidation processes that may help with the rational development of NOS inhibitors. Peroxoiron(III) porphyrin species are now readily accessible in aqueous solution at ambient temperature. Rapid kinetic techniques have been developed to study the reactivity of these species. A central question is how to modulate the chemistry of these complexes between nucleophilic and electrophilic pathways that are essential to understand the variety of P450 mediated processes. Synthetic and semi-synthetic phospholipid assemblies are used to model and understand the larger scale events in P450 and NOS action and to probe the permeability of membranes to reactive oxygen species. Membrane binding by amphiphilic metalloporphyrins is extraordinarily sensitive to pH. This is an unprecedented observation that may have immediate application to the design of metallopharmaceuticals.