FUNCTIONAL ANALOGUES OF 02 BINDING/ACTIVATING HEME SITES

描述：(申请人摘要)本项目的第一个长期目标 研究是为了了解末端氧化酶的催化机制， 细胞色素c氧化酶。这将通过合成和 分子中氧结合活化位的功能模型表征 细胞色素c氧化酶。将使用新开发的方法来制备铁 含三齿铜配合物的卟啉类化合物 卟啉和咪唑轴向配体共价连接到近端 脸。这些模型将通过X射线衍射和一系列 光谱方法的一部分。每个模型复合体都将作为推定的 氧的四电子还原电极催化剂。它的作用机制 将探索这些电催化反应；每个阶段都将 单独检查；将对中间体进行表征。人们希望， 这些催化剂的功能将有助于我们理解酶 反应，尤指幼崽的角色。第二个目标是了解 远端残基在控制相对平衡中的作用 三种天然气态配体的结合：O2、CO和NO。这 将通过研究新的空腔卟啉三明治和 树枝状卟啉。末端空间效应和氢键的作用 将会被探索。NO结合与许多医学问题有关 与气态激素的激活有关，NO。示例包括 血管扩张和神经传递。

DESCRIPTION: (applicant's abstract) The first long-term objective of this research is to understand the catalytic mechanism of the terminal oxidase, cytochrome c oxidase. This is to be accomplished by synthesizing and characterizing functional models of the dioxygen binding activation site in cytochrome c oxidase. Newly developed methods will be used to prepare Fe porphyrins fitted with tridentate Cu complexes on the distal face of the porphyrin and imidazole axial ligands covalently attached to the proximal face. These models will be characterized by X-ray diffraction and a range of spectroscopic methods. Each model complex will be examined as a putative electrode catalyst for the 4-electron reduction of O2. The mechanism of these electrocatalytic reactions will be explored; each stage will be examined separately; intermediates will be characterized. It is hoped that the function of these catalysts will help us understand the enzymatic reaction, especially the role of CuB. A second objective is to understand the role which distal residues play in controlling the relative equilibrium binding of three naturally occurring gaseous ligands: O2, CO, and NO. This will be accomplished by studying new cavity porphyrin sandwiches and dendrite porphyrins. The role of distal steric effects and of H-bonding will be explored. The NO binding has relevance to many medical problems related to activation by the gaseous hormone, NO. Examples include vasodilation and neurotransmission.