O2 Activation by Mossbauer Spectroscopy

说明(申请人提供)：本提案旨在阐明与氧气活化有关的含铁酶的结构和功能。此外，还建议研究各种含有Fe(IV)的合成化合物，这些化合物模仿所研究的酶的活性中心的结构和电子特征。此外，还建议研究过表达的大肠杆菌细胞中蛋白质的穆斯堡尔谱。所采用的实验技术是穆斯堡尔谱、电子顺磁共振(EPR)和SQUID磁测量。还建议用密度泛函理论研究蛋白质的高价Fe(IV)中心和模型络合物。 (1)继续研究二铁蛋白甲烷单加氧酶、核苷酸还原酶、Delta9脱饱和酶和酚羟基酶。 (2)这项研究将得到模型络合物研究的补充，以深入了解酶活性中心的电子结构。 (3)对在大肠杆菌中过表达的含铁蛋白质的全细胞研究将继续进行。 (4)研究了从嗜热菌中分离到的细胞色素P450化合物I的穆斯堡尔谱和电子顺磁共振谱。 (5)将对四种怀疑在催化循环中通过Fe(IV)=O中间体的非血红素铁蛋白进行穆斯堡尔和EPR研究。 (6)用密度泛函理论研究了酶和模型络合物中的铁(IV)位。

DESCRIPTION (provided by applicant): This proposal seeks to elucidate the structure and function of iron-containing enzymes involved in oxygen activation. Moreover, it is proposed to study a variety of Fe(IV) containing synthetic compounds that mimic structural and electronic features of the active sites of the enzymes under study. Further, it is proposed to study the Mossbauer spectra of proteins in overexpressing E. coli cells. The experimental techniques employed are Mossbauer spectroscopy, Electron paramagnetic resonance (EPR) and SQUID magnetometry. It is also proposed to study high-valent Fe(IV) sites of proteins and model complexes with density functional theory. (1) Studies of the diiron proteins methane monooxygenase, ribonucleotide reductase, delta9 desaturase and phenolhydroxylase will be continued. (2) This research will be complemented by studies of model complexes to gain insight into the electronic structure of the active sites of the enzymes. (3) Whole-cell studies of iron containing proteins overexpressed in E. coli will be continued. (4) The Mossbauer and EPR spectra of compound I of cytochrome P450 isolated from a thermophilic bacterium will be studied. (5) Mossbauer and EPR studies of four non-heme iron proteins suspected to pass in their catalytic cycles through an Fe(IV)=O intermediate will be performed. (6) Iron(IV) sites occurring in enzymes and model complexes will be investigated with density functional theory.