OXYGEN UTILIZING MEMBRANE HEME PROTEINS

该项目的目标是利用膜血红素氧 蛋白质是表征前列腺素H酶的结构 （GHS）和细胞色素c氧化酶（CcOX） 在催化过程中发生的变化，因为这些酶与它们的 基质和生物膜。PGHS催化初始步骤 前列腺素类的生物合成--前列腺素的形成 来自花生四烯酸的内过氧化物H2，两个O2分子和两个 电子。CcOX是呼吸电子的末端血红素/Cu氧化酶。 转移链，其催化O2至2的净四电子还原 H2O分子，伴随着四个质子跨 线粒体内膜（或细菌质膜）。有 五个项目和四个核心。项目I：环氧合酶催化和 自杀失活（史密斯）将检查花生四烯酸与 PGHS的环氧合酶位点，自杀失活机制， H20通道在PGHS中的作用 项目二：结构生物学 PGH合成酶（Garavito）的过氧化作用将检查结构 PGHS中过氧化物酶催化的方面，并辨别结构基础 PGHS-1和PGHS-2的过氧化活性的差异。 项目III：PGH合成酶-1和-2中的单位膜修饰物（DeWitt） 将检验PGHS-1和PGHS-2与单个 通过四个疏水面的膜双层的小叶 存在于氨基末端三分之一的连续的两亲性螺旋， proteins.项目IV：解决细胞色素c中的底物对接 细胞色素氧化酶和PGH合酶的光谱学（Babcock） 旨在了解CcOX和PGHS对氧气和过氧化物的活化作用 以及还原过程中释放自由能的机制 这些基板。核心A。给药（Smith），核心B：膜 蛋白质表达和纯化（DeWitt），核心C：结晶和 X射线晶体学（Garavito）和核心D：EPR和共振拉曼 光谱（麦克拉肯）提供行政和技术支持， 这些项目。

The goal of this Program Project entitled Oxygen Utilizing Membrane Heme Proteins is to characterize the structures of prostaglandin H synthases (GHSs) and cytochrome c oxidase (CcOX) in the context of the chemical changes that occur during catalysis as these enzymes interact with their substrates and with biological membranes. PGHS catalyzes the initial step in the biosynthesis of prostanoids--the formation of prostaglandin endoperoxide H2 from arachidonic acid, two molecules of 02 and two electrons. CcOX is a terminal heme/Cu oxidase of the respiratory electron- transfer chain which catalyzes a net four electron reduction of 02 to two H20 molecules with concomitant translocation of four protons across the mitochondrial inner membrane (or bacterial plasma membrane). There are five projects and four cores. Project I: Cyclooxygenase Catalysis and Suicide Inactivation (Smith) will examine the binding of arachidonate to the cyclooxygenase site of PGHS, the mechanism of suicide inactivation and the role of H20 channels in PGHS. Project II: Structural Biology of Peroxidation by PGH Synthases (Garavito) will examine the structural aspects of peroxidase catalysis in PGHSs and discern the structural basis for the differences in the peroxidative activities of PGHS-1 and -2. Project III: Monotopic Membrane Anchors in PGH Synthases-1 and -2 (DeWitt) will test the hypothesis that PGHS-1 and PGHS-2 associate with a single leaflet of the membrane bilayer through hydrophobic faces of four contiguous amphipathic helices present in the amino-terminal third of the proteins. Project IV: Substrate Docking in Cytochrome c resolved Spectroscopy of Cytochrome Oxidases and PGH Synthases (Babcock) is designed to understand oxygen and peroxide activation by CcOX and PGHSs and the mechanisms by which the free energy is released in the reduction of these substrates. Core A. Administration (Smith), Core B: Membrane Protein Expression and Purification (DeWitt), Core C: Crystallization and X-ray Crystallography (Garavito) and Core D: EPR and Resonance Raman Spectroscopy (McCracken) provide administrative and technical support for these projects.