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Title: Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center

Authors:
; ; ; ; ; ; ; ORCiD logo; ; ORCiD logo
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
OTHER U.S. GOVERNMENTNIHOTHER
OSTI Identifier:
1376251
Resource Type:
Journal Article
Resource Relation:
Journal Name: Biochemistry; Journal Volume: 56; Journal Issue: 22
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Sui, Xuewu, Weitz, Andrew C., Farquhar, Erik R., Badiee, Mohsen, Banerjee, Surajit, von Lintig, Johannes, Tochtrop, Gregory P., Palczewski, Krzysztof, Hendrich, Michael P., and Kiser, Philip D. Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center. United States: N. p., 2017. Web. doi:10.1021/acs.biochem.7b00251.
Sui, Xuewu, Weitz, Andrew C., Farquhar, Erik R., Badiee, Mohsen, Banerjee, Surajit, von Lintig, Johannes, Tochtrop, Gregory P., Palczewski, Krzysztof, Hendrich, Michael P., & Kiser, Philip D. Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center. United States. doi:10.1021/acs.biochem.7b00251.
Sui, Xuewu, Weitz, Andrew C., Farquhar, Erik R., Badiee, Mohsen, Banerjee, Surajit, von Lintig, Johannes, Tochtrop, Gregory P., Palczewski, Krzysztof, Hendrich, Michael P., and Kiser, Philip D. Wed . "Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center". United States. doi:10.1021/acs.biochem.7b00251.
@article{osti_1376251,
title = {Structure and Spectroscopy of Alkene-Cleaving Dioxygenases Containing an Atypically Coordinated Non-Heme Iron Center},
author = {Sui, Xuewu and Weitz, Andrew C. and Farquhar, Erik R. and Badiee, Mohsen and Banerjee, Surajit and von Lintig, Johannes and Tochtrop, Gregory P. and Palczewski, Krzysztof and Hendrich, Michael P. and Kiser, Philip D.},
abstractNote = {},
doi = {10.1021/acs.biochem.7b00251},
journal = {Biochemistry},
number = 22,
volume = 56,
place = {United States},
year = {Wed Apr 26 00:00:00 EDT 2017},
month = {Wed Apr 26 00:00:00 EDT 2017}
}
  • NO forms reversible complexes with non-heme ferrous enzymes and model complexes which exhibit unusual S = 3/2 ground states. These nitrosyl derivatives can serve as stable analogs of possible oxygen intermediates in the non-heme iron enzymes. Two complexes, Fe(Me[sub 3]TACN)(NO)(N[sub 3])[sub 2] and FeEDTA-NO, have been studied in detail using X-ray absorption, resonance Raman, absorption, magnetic circular dichroism. and electron paramagnetic resonance spectroscopies and SQUID magnetic susceptibility. These studies have been complemented by spin restricted and spin unrestricted SCF-X[Alpha]-SW electronic structure calculations. As these calculations have been strongly supported by experiment for the nitrosyl complexes, they have been extended tomore » possible oxygen intermediates. In parallel with the Fe[sup 3+]-NO[sup [minus]] complexes, the description of the intermediate obtained involves superoxide antiferromagnetically coupled to a high spin ferric center with a strong [sigma] donation of charge from the superoxide to the iron. These studies allow spectral data on the nitrosyl complexes to be used to estimate bonding differences in possible oxygen intermediates of different non-heme iron proteins and provide insight into the activation of superoxide by coordination to the ferric center for reaction or further reduction. 75 refs., 17 figs., 9 tabs.« less
  • The geometric and electronic structure of high-spin ferrous complexes of bleomycin (Fe{sup II}BLM) and the structural analog PMAH ([Fe{sup II}PMA]{sup +}, where PMAH is a macrocyclic ligand with pyrimidine, imidazole, deprotonated amide, and secondary and primary amine functionalities) have been investigated by optical (Abs) and X-ray (XAS) absorption, magnetic circular dichroism (MCD), and resonance Raman (rR) spectroscopies. The lability of high-spin iron combined with steric constraints of the BLM ligand framework and its weaker axial interaction with solvent support a dissociative mechanism for O{sub 2} reactivity. Our spectroscopic studies of solid [Fe{sup II}PMA]{sup +} have defined the nature of suchmore » a five-coordinate intermediate as square pyramidal which provides an open coordination position for reaction with O{sub 2}. A major electronic structure difference between Fe{sup II}BLM (and [Fe{sup II}PMA]{sup +}) and other non-heme ferrous sites is the presence of low-energy CT transitions which reflect strong iron(II) {yields} pyrimidine backbonding. Despite generally being considered a non-heme iron system due to the absence of an extensive delocalized {pi} network, the existence of low-energy MLCT transitions with reasonable intensity, hence the presence of some backbonding, identifies BLM as an important link bridging the chemistry of non-heme and heme active sites. 113 refs., 17 figs., 4 tabs.« less
  • No abstract prepared.
  • Non-heme iron centers are present in the catalytic active sites of a large number of enzymes which are involved in the binding and activation of dioxygen. A member of this class, soybean lipoxygenase (SBL), catalyzes the reaction of 1,4-unsaturated lipids with dioxygen to form a hydroperoxide product. Nitrosyl complexes of enzymes serve as reversible analogues of possible dioxygen intermediates involved in catalysis. SBL-NO and other non-heme ferrous enzyme nitrosyl complexes (formulated as (FeNO){sup 7}) exhibit an unusual S = {sup 3}/{sub 2}{sub 3}EPR signal, which is also observed in (FeNO){sup 7} model complexes. A wide range of bonding descriptions havemore » appeared for these complexes, which include [Fe{sup +}d{sup 7}(S = 3/2)-NO{sup +}(S = O)], [Fe{sup 2+}d{sup 6}(S=2)-NO{sup 0}(S=1/2)] antiferromagnetically coupled, [Fe{sup 3+}d{sup 5}(S =1/2)-NO{sup {minus}}(S = 1)] ferromagnetically coupled, and [Fe{sup 3+}d{sup 5}(S = 3/2)-NO{sup {minus}}(S=0)]. In order for the NO derivative of these enzymes to be used as a probe of electron distribution related to dioxygen reactivity, a clear understanding of the electronic structure and associated spectral features of the S = 3/2 (FeNO){sup 7} unit is required. Spectroscopic techniques and theoretical methods have been used to study SBL-NO and two S = 3/2 ground-state model complexes, FeL-(NO)(N{sub 3}){sub 2}, where L = N,N{prime},N{double_prime}-trimethyl-1,4,7-triazacyclononane and FeEDTA-NO. 20 refs., 2 figs.« less