Problems in Bioinorganic and Metal Cluster Chemistry

该奖项在无机，生物无机和有机化学计划支持生物无机化学和金属簇的研究由博士理查德H。哈佛大学化学系的霍尔姆说。 将进行四方面的调查。 在第一个专题领域，将检查酶二甲基亚砜还原酶，硝酸还原酶和甲酸脱氢酶的催化位点的准确的最小合成表示。 酶促转化的途径和这些途径的可行性的因素将进行探讨。 第二个研究领域涉及与氢化酶有关的生物学相关的镍和铁化学。 将制备设计用于稳定两种金属的硫醇盐桥接排列的四半胱氨酰环肽。 将在所得模型化合物中研究氢吸收和演化的动力学。 第三个领域包括过氧化物桥连的血红素-铜物种的合成和铁-铜磁耦合的研究，这是血红素-铜氧化酶的一个重要性质。 还将研究含卟啉的铁铜配合物与过氧化物和酶抑制剂氰化物的相互作用。 最后，介观尺度的金属硫族化合物团簇的合成和表征。 这些簇将包含硫或硒，并通过桥接相互作用连接。金属在各种酶的活性中起着重要作用，但控制其活性的因素还不完全清楚。 在这里，将合成模拟许多酶的化合物，并研究结构和电子变化对作用模式的影响。 一个潜在的结果是在分子水平上描述氰化物在好氧生物体中的毒性基础。 参与调查的研究生将学习各种先进的光谱方法，并将受益于参与包括其他机构合作者的计划。

This award in the Inorganic, Bioinorganic, and Organometallic Chemistry program supports research in bioinorganic chemistry and in metal clusters by Dr. Richard H. Holm of the Chemistry Department, Harvard University. Four lines of investigation will be pursued. In the first topical area, accurate minimal synthetic representations of the catalytic sites of the enzymes dimethylsulfoxide reductase, nitrate reductase, and formate dehydrogenase will be examined. Pathways for enzymatic transformations and the factors contributing to the feasibility of these pathways will be explored. The second area of research involves biologically related nickel and iron chemistry pertinent to the enzyme hydrogenase. Tetracysteinyl cyclic peptides designed to stabilize the thiolate-bridged arrangement of the two metals will be prepared. The kinetics of dihydrogen uptake and evolution will be studied in the resulting model compounds. The third area includes synthesis of a peroxide-bridged heme-copper species and investigation of magnetic coupling between iron and copper, an imporant property of heme-copper oxidases. Interactions of porphyrin-containing iron-copper complexes with peroxide and the enzyme inhibitor cyanide will also be studied. Finally, mesoscale metal chalcogenide clusters will be synthesized and characterized. The clusters will contain rhenium and sulfur or selenium and will be linked by bridging interactions.Metals play important roles in the activity of a wide range of enzymes, but factors controlling their activity are not entirely understood. Here compounds modeling a number of enzymes will be synthesized and the effect of structural and electronic changes on mode of action will be studied. One potential outcome is a molecular level description of the basis of cyanide toxicity in aerobic organisms. Graduate students involved in the investigation will learn a wide variety of advanced spectroscopic methods and will benefit from involvement in a program that includes collaborators at other institutions.