Biophysical Studies of Metalloenzymes

点击翻译按钮获取中文摘要

HoffmanMCB 9904018The objective of this research is to further develop a unique multifrequency capacity to perform and analyze advanced paramagnetic resonance (amr) spectroscopies (electron-nuclear double resonance, endor; electron spin-echo envelope modulation, eseem) as a powerful, selective, and sensitive ally to X-ray crystallography for characterizing metalloenzyme active sites and their interactions with substrates/inhibitors/products, both in the resting state and in key intermediates. The amr studies of metalloenzymes will emphasize three areas: (I) The amr of integer-spin, systems with high spin (S 1), but which exhibit an epr-active, ground-state Non-Kramers doublet; (II) Substrate and inhibitor interactions with the molybdenum-iron cofactor of the nitrogenase MoFe protein; and (III) The mechanism of methane production by Methyl-coenzyme M reductase (MCR) isolated from Methanobacterium thermoautotrophicum. Metal ions are pervasive in biology; no less than one-third of all proteins and enzymes require metal ions as cofactors. This program seeks to develop and apply advanced paramagnetic resonance (amr) spectroscopies as a powerful, selective, and sensitive ally to X-ray crystallography for characterizing metalloenzyme active sites and their interactions with substrates, both in the resting state and in key intermediates. In addition to the development of new methodologies, this program is engaged in the study of the environmentally and agriculturally important enzyme, nitrogenase, and in the study of the production of the greenhouse gas, methane, by a bacterial enzyme, Methyl-coenzyme M reductase, isolated from Methanobacterium thermoautotrophicum.