CYTOCHROME P450 INTERACTION W/ CYTOCHROME B5: NMR

我们这个项目的总体长期目标是了解 细胞色素b5（cyt b5）对细胞凋亡影响的分子基础 细胞色素P450（cyt P450）代谢某些底物， 确定这种反应的生理意义。 在 特别是，我们有兴趣阐明的分子基础， 细胞色素B5对代谢的显著刺激作用， 通过cyt P450 LM2（2B4）测定挥发性麻醉剂甲氧氟烷。 这些 研究可能最终导致病因的描述， 术后肝毒性的病理生理学归因于 挥发性麻醉剂和更安全的麻醉剂的发展。 这些研究还应提供关于 细胞色素P450氧化其大量内源性和 异生物质基质 这些知识应该证明是有价值的， 促进临床上有用的细胞色素抑制剂的设计 P450用于真菌疾病的治疗应用， 醛固酮增多症、前列腺癌、良性前列腺肥大和 乳腺癌 我们建议的更直接目标是利用 23，000道尔顿的细胞色素b5-细胞色素c（cyt c）复合物作为 较大的（72，000道尔顿）疏水性细胞色素b5-细胞色素P450复合物，和 使用高分辨率确定模型复合体的结构 匪r 细胞色素b5-细胞色素c复合物是一个相关的模型， 更大的疏水复合物，因为细胞色素b5使用 与细胞色素c相互作用的位点大致相同， 细胞色素P450 细胞色素B5-细胞色素C的结构知识 复杂的将提供洞察1）机制，2）途径， 电子转移，在细胞色素b5和它的氧化还原配偶体之间，和3） 大分子识别和蛋白质动力学。 计算机， 加州大学旧金山分校计算机实验室的图形和编程设施 已经并将用于构建三维分子 基于我们的NMR研究结果的模型，以显示和检查 这些模型，并计算动力学和相互作用的 模型中的组件。 这些结果将导致更大的 理解对cyt要求的一些结构基础 b5为细胞色素P450对某些底物的代谢。

Our overall long-term goal of this project is to understand the molecular basis of the effect of cytochrome b5 (cyt b5) on the metabolism of certain substrates by cytochrome P450 (cyt P450), and to determine the physiological significance of this reaction. In particular, we are interested in elucidating the molecular basis of the marked stimulatory effect of cyt b5 on the metabolism of the volatile anesthetic, methoxyflurane, by cyt P450 LM2 (2B4). These studies may eventually lead to the delineation of the etiology and pathophysiology of the postoperative hepatotoxicity attributed to the volatile anesthetics and to the development of safer anesthetics. These studies should also provide important information about the mechanism by which cyt P450 oxidizes its numerous endogenous and xenobiotic substrates. This knowledge should prove valuable in facilitating the design of clinically useful inhibitors of cytochrome P450 for therapeutic applications in fungal diseases, hyperaldosteronism, prostate cancer, benign prostatic hypertrophy and breast cancer. The more immediate goal of our proposal is to use the 23,000 dalton cyt b5-cytochrome c (cyt c) complex as a model for the larger (72,000 dalton) hydrophobic cyt b5-cyt P450 complex and determine the structure of the model complex using high resolution NMR. The cytochrome b5-cytochrome c complex is a relevant model for the larger hydrophobic complex because cytochrome b5 uses approximately the same site to interact with both cytochrome c and cytochrome P450. Knowledge of the structure of the cyt b5-cyt c complex will provide insights into 1) the mechanism, 2) pathway of electron transfer, between cyt b5 and its redox partners and 3) macromolecular recognition and protein dynamics. The computing, graphics and programming facilities at the UCSF Computer Laboratory have been and will be used to construct three-dimensional molecular models based on results from our NMR studies, to display and examine these models, and to calculate the dynamics and interactions of the components in the models. These results should lead to a greater understanding of some the structural basis for the requirement for cyt b5 for the metabolism of some substrates by cyt P450.