EXCITED STATES IN METALLOPROTEINS

分子氧在生物学中起着重要的作用 有效保存能量所需的氧化代谢。 因此，氧和相关配体与 血红素蛋白如肌红蛋白、血红蛋白、细胞色素氧化酶、细胞色素 P-450和过氧化氢酶构成了 运输、储存和还原这种无处不在的氧化剂。 因此，该项目的具体目标集中在 氧气输送的生理和生物医学重要方面， 在组织中的应用。 此外，一氧化碳和一氧化氮 衍生物是已知的空气污染物。 血红素蛋白一氧化氮 络合物经常作为中间体和/或副产物被观察到 固氮作用，含氮致癌物的代谢。 的 提出了各种血红素蛋白相互作用模式的研究 与氧和相关的气体配体将提供深刻的 关于结构和电子机制的信息 血红素蛋白与这些配体的相互作用。 我们正在测量 各种血红蛋白-配体复合物的瞬态吸收光谱 在以皮科至微秒的时间尺度进行激光照射之后， 测定在辐照时的孪合态和脱氧态的量 环境温度和估计表观量子效率 这些系统。 此外，相同系统的光解将被 在低温下测量表观量子 将它们关联为温度的函数的效率， 分子结构

Molecular oxygen plays fundamental roles in the biological oxidative metabolism required for efficient conservation of energy. Therefore, the interactions of oxygen and related ligands with hemoproteins like myoglobin, hemoglobin, cytochrome oxidase cytochrome P-450, and hydroperoxidases constitute the elementary steps in transport, storage and reduction of this ubiquitous oxidant. Therefore, the specific aims of this project sharply focus on the physiological and biomedically vital aspects of oxygen delivery to and utilization in tissues. Furthermore, carbon monoxide and nitric oxide derivatives are known air pollutants. Hemoprotein nitric oxide complexes are frequently observed as intermediates and/or byproducts of nitrogen fixation, metabolism of nitrogenous carcinogens. The proposed studies of the modes of interaction of various hemoproteins with oxygen and related gaseous ligands will provide incisive information regarding the structural and electronic mechanism of interactions of hemoproteins with these ligands. We are measuring transient absorption spectra of various hemoprotein-ligand complexes after laser irradiation at time scales of pico- to microseconds to determine the amounts of geminate and deoxy states upon irradiation at ambient temperature and to estimate apparent quantum efficiencies of these systems. In addition, photolysis of the same systems will be performed at cryogenic temperatures to measure apparent quantum efficiencies to correlate them as a function of temperature and molecular structure.