SPECTROSCOPY OF BIOLOGICAL SATURATED PORPHYRINS

本项目涉及详细假肢的研究。 含氯和饱和卟啉的基团结构 蛋白质和酶。在之前的授权期内，我们 已确定的特征和确定的红外(IR)和 金属氯化物的共振拉曼光谱性质 对氯素大循环的诊断是一致的 生物系统和模型系统。在目前的提案中，我们提议 将这些研究扩展到以下系统：1)绿色 来自大肠杆菌的血红素d末端氧化酶被认为是一种 二醇氯或内酯氯。我们将检查RR谱 纯化的大肠杆菌血红素d复合体的不同自旋和 氧化态与二元醇和内酯取代物的比较 用于确定血红素d体内结构的模型络合物 大循环。2)肌红蛋白(Mb)的绿色形态 暴露在硫磺化合物中，硫磺Mb会产生硫磺修饰的铁 氯仿假体组。哺乳动物的酶 乳过氧化物酶(LPO)和甲状腺过氧化物酶(TPO)受到抑制 被称为甲状腺激素的硫磺药物，在类似的反应中 这导致了硫化Mb的形成。我们建议确定 磺化LPO的假体基团是否真的是硫化氯， 并阐明了观测到的UV-Vis光谱的结构来源 硫化LPO与硫化Mb的区别。我们还将延长 稳定性好、可萃取性好的亚硫氯体系研究 来自SulMb的亚硫胺，如果可能的话，SulLPO，以及模型 亚硫氯络合物。3)纯化细胞色素CD1 细菌亚硝酸还原酶。铜绿假单胞菌和分离出的 绿血红素D_1假体组检测光谱 二氧异细菌碘氯(卟啉)的特性。我们 将比较纯化的CD1酶和它的 分离的D1型假体与各种体位的假体 和取代异构体的氧代氯和二氧代ibc模型 复合体。4)我们计划将这些研究扩展到分析 铁血红素和更高饱和度的卟啉，例如， 四氢卟啉和六氢卟啉，以建立 特定于每种饱和程度的光谱特性 卟啉。5)肌红蛋白和其他血红素蛋白将 与铁的氯化物络合物重组。我们将研究 这些氯蛋白在所有可获得的自旋中的光谱性质- 和氧化态，以及配体络合物 与不含蛋白质的模型络合物结合。

This project concerns the investigation of the detailed prosthetic group structure of chlorin and saturated porphyrin-containing proteins and enzymes. In the previous grant period, we established characteristic and definitive infrared (IR) and resonance Raman (RR) spectral properties of metallochlorins that are consistently diagnostic for the chlorin macrocycle in biological and model systems. In the current proposal we propose to extend those studies to the following systems: 1) The green heme d terminal oxidase from E. coli is proposed to be either a diol chlorin or a lactone chlorin. We will examine the RR spectra of the purified E. coli heme d complex in its various spin- and oxidation-states in comparison with diol and lactone substituted model complexes to determine the in vivo structure of the heme d macrocycle. 2) The green form of myoglobin (Mb) induced by exposure to sulfur compounds, sulfMb, has a sulfur-modified iron chlorin prosthetic group. The mammalian enzymes lactoperoxidase (LPO) and thyroid peroxidase (TPO) are inhibited by sulfur drugs known as goitrogens, in a reaction similar to that which leads to the formation of sulfMb. We propose to determine whether the prosthetic group of sulfLPO is indeed a sulf-chlorin, and elucidate the structural origin of the observed UV-vis spectral differences between sulfLPO and sulfMb. We will also extend the studies on sulfchlorin systems to include the stable, extractable sulfhemes from sulfMb, and if possible sulfLPO, as well as model sulfchlorin complexes. 3) We will purify the cytochrome cd1 bacterial nitrite reductase from Ps. aeruginosa and isolate the green heme d1 prosthetic group to examine spectral characteristics of dioxoisobacteriochlorins (porphyrindione). We will compare the properties of the purified cd1 enzyme and its isolated d1 prosthetic group with those of a variety of positional and substitutional isomers of oxo-chlorin and dioxo-iBC model complexes. 4) We plan to extend these studies to the analysis of sirohemes and more highly saturated porphyrins, e.g., tetrahydroporphyrins and hexahydroporphyrins, to establish spectral properties which are specific for each level of saturated porphyrin. 5) Myoglobin and other heme proteins will be reconstituted with iron chlorin complexes. We will examine the spectral properties of these chlorin-proteins in all accessible spin- and oxidation-states, as well as ligand complexes, in comparison with the protein-free model complexes.