CRYSTALLOGRAPHY OF BRAIN NITRIC OXIDE SYNTHASE REDUCTASE

脑一氧化氮合酶还原酶的晶体学

• 批准号: 6119545
• 负责人: CHRISTOPHER M BRUNS
• 金额: --
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2000-04-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6119545
• 关键词: biomaterials; nervous system; proteins; structural biology

We aim to determine the atomic structure of the 70kD reductase domain of nitric oxide synthase from the brain. Nitric oxide (NO) is an important molecule in intercellular signalling. Nitric oxide synthase (NOS) is a large polypeptide, responsible for the production of NO. The crystal structure of one half of inducible nitric oxide synthase (the 70kD oxygenase domain, using data collected at SSRL) has been determined, but the structure of the 70kD reductase domain remains unknown. The reductase domain of nitric oxide synthase binds three redox active cofactors: FMN, FAD, and NADPH. These constitute the first three electron carriers in the electron transport chain that results in production of NO. At present the structural mechanism by which these cofactors supply electrons to the heme group of the oxygenase domain is unknown. We have obtained two crystal forms of brain NOS reductase domain (bNOSr). On our laboratory X-ray source, these crystals seldom diffract to better than 6 E resolution; however, preliminary tests at synchrotron X-ray sources have shown diffraction to 2.7 E. Therefore, synchrotron radiation is necessary to obtain X-ray diffraction data to reasonable resolution for structure determination. We are confident that with improved crystallization conditions, this limit can be further improved. We have obtained preliminary phasing information using a homologous molecular replacement search model, but we require higher quality diffraction data in order to complete the project. Our goal is to collect high quality diffraction data for bNOSr in the native form and in complex with inhibitors.

我们旨在确定70KD还原酶的原子结构 一氧化氮合酶的结构域。 一氧化氮（否）是 细胞间信号传导中的重要分子。 一氧化氮 合酶（NOS）是一个大多肽，负责生产 否。 一半诱导一氧化氮的晶体结构 合成酶（使用SSRL收集的数据的70KD氧合酶结构域）已有 已确定，但是70KD还原酶结构域的结构 仍然未知。 一氧化氮合酶的还原酶结构域结合 三个氧化还原活性辅助因子：FMN，FAD和NADPH。 这些构成 电子传输链中的前三个电子载体 导致No的生产。 目前是结构机制 这些辅助因子将电子提供给电子血红素组 氧合酶结构域是未知的。 我们获得了两种晶体形式的 脑NOS还原酶结构域（BNOSR）。 在我们的实验室X射线源上， 这些晶体很少衍射到比6 e分辨率更好。然而， 同步子X射线源的初步测试已显示出衍射 到2.7 E.因此，必须进行同步辐射以获得 X射线衍射数据至合理的结构分辨率 决心。 我们有信心通过改进的结晶 条件，该限制可以进一步提高。 我们已经获得了 使用同源分子的初步分阶段信息 替换搜索模型，但我们需要更高质量的衍射 数据以完成项目。 我们的目标是收集 BNOSR的质量衍射数据以天然形式和复杂 与抑制剂。