SPECTROSCOPY OF BIOLOGICAL SATURATED PORPHYRINS

生物饱和卟啉的光谱学

• 批准号: 3285509
• 负责人: THOMAS M LOEHR
• 金额: $ 14.68万
• 依托单位: OREGON GRADUATE INSTITUTE SCIENCE & TECH
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-12-01 至 1991-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3285509
• 关键词: Escherichia coli; Neurospora; Pseudomonas aeruginosa; Raman spectrometry; catalase; chlorin; chlorophyll; circular magnetic dichroism; diol; hemoprotein; lactones; lactoperoxidase; ligands; metal complex; metalloenzyme; metalloporphyrins; molecular site; myoglobin; nitrites; nuclear magnetic resonance spectroscopy; oxidation reduction reaction; porphyrin biosynthesis; porphyrin structure; protein reconstitution; thyroid inhibitor

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.

该项目涉及详细假肢的研究 二氢卟酚和饱和卟啉的基团结构 蛋白质和酶。 在上一个资助期内，我们 确定的特征和确定的红外 (IR) 和 金属二氢卟酚的共振拉曼 (RR) 光谱特性 一致地诊断二氢卟酚大环 生物和模型系统。 在当前提案中，我们建议 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 二醇二氢卟酚或内酯二氢卟酚。 我们将检查 RR 光谱 纯化的大肠杆菌血红素 d 复合物在其各种旋转和 与二醇和内酯取代物相比的氧化态 模型复合物以确定血红素 d 的体内结构 大周期。 2) 诱导的绿色形式的肌红蛋白 (Mb) 暴露于硫化合物 sulfMb，具有硫改性铁 二氢卟酚辅基。 哺乳动物酶 乳过氧化物酶 (LPO) 和甲状腺过氧化物酶 (TPO) 受到抑制 被称为甲状腺肿素的含硫药物，​​其反应类似于 这导致 sulfMb 的形成。 我们建议确定 sulfLPO的辅基是否确实是硫二氢卟酚， 并阐明观察到的紫外-可见光谱的结构起源 sulfLPO 和 sulfMb 之间的差异。 我们还将延长 对硫氯系统的研究包括稳定的、可提取的 来自 sulfMb 的 sulfhemes，如果可能的话 sulfLPO，以及模型 硫氯络合物。 3）我们将纯化细胞色素cd1 来自 Ps 的细菌亚硝酸还原酶。铜绿假单胞菌并分离 用于检查光谱的绿色血红素 d1 假体组 二氧化异细菌二氢卟酚（卟啉二酮）的特征。 我们 将比较纯化的 cd1 酶及其 孤立的 d1 假体组与各种位置的假体组 氧代二氢卟酚和二氧代-iBC 模型的取代异构体 复合物。 4）我们计划将这些研究扩展到分析 西罗血红素和更高度饱和的卟啉，例如， 四氢卟啉和六氢卟啉，建立 每个饱和水平特定的光谱特性 卟啉。 5) 肌红蛋白和其他血红素蛋白将 用铁二氢卟酚络合物重构。 我们将检查 这些二氢卟酚蛋白质在所有可及的自旋中的光谱特性 和氧化态，以及配体配合物，比较 与无蛋白质模型复合物。