X-Ray and Chemical Studies of Metalloporphyrins

金属卟啉的 X 射线和化学研究

• 批准号: 6772747
• 负责人: W. ROBERT SCHEIDT
• 金额: $ 32.85万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-05-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6772747
• 关键词: Mossbauer spectrometry; X ray crystallography; chemical property; chemical synthesis; electrical property; electron spin resonance spectroscopy; heme; hemoprotein; hemoprotein structure; infrared spectrometry; intermolecular interaction; iron compounds; metalloporphyrins; physical property; porphyrin structure; quantum chemistry; stereochemistry; ultraviolet spectrometry

DESCRIPTION (provided by applicant): The synthesis and characterization of a variety of new metalloporphyrin compounds is proposed. The work will emphasize, but will not be limited to, iron porphyrinate derivatives. Most classes of compounds proposed for study are related to hemoprotein derivatives, which carry out a wide range of biological functions including oxygen utilization, storage and transport, NO-based signaling, electron transport, drug metabolism and other enzymatic processes. The methods of three-dimensional X-ray crystal structure determination will be applied to define molecular structures and various detailed aspects of metalloporphyrin stereochemistry. The new technique of nuclear resonance vibrational spectroscopy (NRVS) is being used to define iron dynamics in biomolecules. The NRVS method allows the observation of all vibrational models in which there is movement of the iron. NRVS has already yielded interesting vibrational data not available by any other technique including the detection of the Fe-Im mode in six-coordinate imidazole-ligated CO derivatives. It will allow an understanding of how the protein environment can change iron dynamics and hence reactivity patterns. Other methodologies to be applied, as appropriate, include characterization of magnetic properties by bulk temperature-dependent susceptibility and electron paramagnetic resonance (EPR) measurements, Mossbauer, vibrational and UV-vis spectroscopy, and electrochemical properties. The research objectives, stated in the broadest terms, are to achieve a synthesis of the structural and physical properties of metalloporphyrins, particularly as these relationships pertain to an understanding of hemoprotein-based biological processes. Iron porphyrinates to be studied include a number of six-coordinate derivatives, [Fe(Por)(XO)(Im)] (XO = O2, CO, NO), in order to examine changes in the Fe-Im vibrations as the opposite ligand is changed, important for understanding issues in hemoglobin oxygen-binding cooperativity. Other projects include detailed study of structure and electronic structure of high-spin five coordinate iron(II) species, additional nitrosyl complexes, synthetic analogues of cytochromes b and c to show how axial ligand orientation affects their electronic structure and oxidation-reduction properties.

描述（由申请人提供）：提出了各种新的金属卟啉化合物的合成和表征。这项工作将强调，但不限于，铁卟啉衍生物。提出用于研究的大多数类别的化合物与血红素蛋白衍生物有关，其执行广泛的生物功能，包括氧利用、储存和运输、基于NO的信号传导、电子传递、药物代谢和其他酶促过程。三维X射线晶体结构测定的方法将被应用于确定分子结构和金属卟啉立体化学的各个细节方面。核共振振动光谱（NRVS）的新技术正在被用来确定生物分子中的铁动力学。NRVS方法允许观察所有存在铁运动的振动模型。NRVS已经产生了有趣的振动数据，而不是通过任何其他技术，包括检测的Fe-Im模式在六配位咪唑连接的CO衍生物。它将允许了解蛋白质环境如何改变铁动力学，从而改变反应模式。其他适用的方法包括通过体温度相关磁化率和电子顺磁共振（EPR）测量、穆斯堡尔、振动和紫外-可见光谱以及电化学性质来表征磁性。研究目标，在最广泛的条款，是实现金属卟啉的结构和物理性质的合成，特别是因为这些关系涉及到基于血红素的生物过程的理解。要研究的铁卟啉盐包括许多六配位衍生物[Fe（Por）（XO）（Im）]（XO = O2，CO，NO），以检查Fe-Im振动的变化，因为相对配体发生变化，这对于理解血红蛋白氧结合协同性问题很重要。其他项目包括详细研究高自旋五配位铁（II）物种的结构和电子结构，额外的亚硝酰基络合物，细胞色素B和c的合成类似物，以显示轴向配体取向如何影响其电子结构和氧化还原特性。