期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2010
卷号：107
期号：9
页码：3982-3987
DOI：10.1073/pnas.0911565107
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Iron oxygenases generate elusive transient oxygen species to catalyze substrate oxygenation in a wide range of metabolic processes. Here we resolve the reaction sequence and structures of such intermediates for the archetypal non-heme FeII and -ketoglutarate-dependent dioxygenase TauD. Time-resolved Raman spectra of the initial species with 16O18O oxygen unequivocally establish the FeIV[boxH]O structure. 1H/2H substitution reveals direct interaction between the oxo group and the C1 proton of substrate taurine. Two new transient species were resolved following FeIV[boxH]O; one is assigned to the{nu} FeO mode of an FeIII[boxh]O(H) species, and a second is likely to arise from the vibration of a metal-coordinated oxygenated product, such as FeII[boxh]O[boxh]C1 or FeII[boxh]OOCR. These results provide direct insight into the mechanism of substrate oxygenation and suggest an alternative to the hydroxyl radical rebinding paradigm.
