MECHANISMS OF REACTIONS OF OXYGEN WITH HEME PROTEINS

将制备血红蛋白和相关血红素蛋白的模型化合物 以及它们的结构对反应动力学的影响 分子氧、一氧化碳和异腈。 双生重组 异氰化物，一氧化氮和双氧的各种模型化合物的R- 以及具有不同空间程度的T-状态血红蛋白和血红素， 电子和极性效应在该网站将研究使用 飞秒、皮秒和纳秒动力学方法。 光解 量子产率将被确定为与动力学相关 问题研究 将作出特别努力，以确定 血红素环番和血红素的结合和构象变化 proteins. 新的化合物将被设计来探索 卟啉柔性、在分子氧作用下的“刚性”变形等 配体结合 合作结合血红素化合物，现在在手， 设计的系统将研究动力学和平衡方面的 一氧化碳和分子氧的结合，以模拟 血红蛋白。 本研究将明确血红素化合物的这些特性及其在生物医学中的应用。 环境，控制这种血红素的不同反应性， 血红素蛋白 这些信息将提供了解 血红蛋白的协同性，蛋白质的构象变化， 其它控制配体亲和力的效应。 环蕃卟啉和二聚体血红素化合物也将用于 探索介入分子结构对 卟啉-卟啉电子转移。

Model compounds for hemoglobin and related hemoproteins will be prepared and the effect of their structure on the dynamics of reaction with dioxygen, carbon monoxide, and isonitriles studied. Geminate recombination of isocyanides, nitric oxide and dioxygen to various model compounds for R- and T-state hemoglobins and hemes with different extents of steric, electronic and polar effects at the site will be studied using femptosecond, picosecond, and nanosecond kinetic methods. Photolysis quantum yields will be determined for correlation with the kinetic studies. Special efforts will be made to determine relative rates of binding and conformational change in both the heme cyclophanes and in heme proteins. New compounds will be designed to explore the effects of porphyrin flexibility, distortion of "stiffness" upon dioxygen and other ligand binding. Cooperatively binding heme compounds now in hand and newly designed systems will be studied with regard to kinetics and equilibria of carbon monoxide and dioxygen binding in order to mimic the cooperativity in hemoglobin. This study will define those characteristics of heme compounds and their environment which control the varied reactivities of such hemes in hemoproteins. This information will provide the means of understanding the cooperativity in hemoglobin, the conformational changes in proteins, and other effects which govern ligand affinity. The cyclophane porphyrins and the dimer heme compounds will also be used to probe the effect of intervening molecular structure on porphyrin-to-porphyrin electron transfer.