scholarly journals Strongly Coupled Redox-Linked Conformational Switching at the Active Site of the Non-Heme Iron-Dependent Dioxygenase, TauD

2019 ◽  
Vol 123 (37) ◽  
pp. 7785-7793 ◽  
Author(s):  
Christopher W. John ◽  
Greg M. Swain ◽  
Robert P. Hausinger ◽  
Denis A. Proshlyakov
Keyword(s):  
Active Site ◽  
Heme Iron ◽  
Conformational Switching ◽  
Strongly Coupled ◽  
Non Heme Iron

Strongly Coupled Redox-Linked Conformational Switching at the Active Site of the Non-Heme Iron-Dependent Dioxygenase, TauD

2019 ◽  
Author(s):  
Christopher John ◽  
Greg M. Swain ◽  
Robert P. Hausinger ◽  
Denis A. Proshlyakov
Keyword(s):  
Active Site ◽  
Structural Model ◽  
Heme Iron ◽  
Chemical Transformations ◽  
Experimental Conditions ◽  
Strongly Coupled ◽  
Non Heme Iron ◽  
Reversible Redox ◽  
Wide Range ◽  
Complex Structural

2-Oxoglutarate (2OG)-dependent dioxygenases catalyze C-H activation while performing a wide range of chemical transformations. In contrast to their heme analogues, non-heme iron centers afford greater structural flexibility with important implications for their diverse catalytic mechanisms. We characterize an <i>in situ</i> structural model of the putative transient ferric intermediate of 2OG:taurine dioxygenase (TauD) by using a combination of spectroelectrochemical and semi-empirical computational methods, demonstrating that the Fe (III/II) transition involves a substantial, fully reversible, redox-linked conformational change at the active site. This rearrangement alters the apparent redox potential of the active site between -127 mV for reduction of the ferric state and 171 mV for oxidation of the ferrous state of the 2OG-Fe-TauD complex. Structural perturbations exhibit limited sensitivity to mediator concentrations and potential pulse duration. Similar changes were observed in the Fe-TauD and taurine-2OG-Fe-TauD complexes, thus attributing the reorganization to the protein moiety rather than the cosubstrates. Redox difference infrared spectra indicate a reorganization of the protein backbone in addition to the involvement of carboxylate and histidine ligands. Quantitative modeling of the transient redox response using two alternative reaction schemes across a variety of experimental conditions strongly supports the proposal for intrinsic protein reorganization as the origin of the experimental observations.

scholarly journals Strongly Coupled Redox-Linked Conformational Switching at the Active Site of the Non-Heme Iron-Dependent Dioxygenase, TauD

2019 ◽  
Author(s):  
Christopher John ◽  
Greg M. Swain ◽  
Robert P. Hausinger ◽  
Denis A. Proshlyakov
Keyword(s):  
Active Site ◽  
Structural Model ◽  
Heme Iron ◽  
Chemical Transformations ◽  
Experimental Conditions ◽  
Strongly Coupled ◽  
Non Heme Iron ◽  
Reversible Redox ◽  
Wide Range ◽  
Complex Structural

2-Oxoglutarate (2OG)-dependent dioxygenases catalyze C-H activation while performing a wide range of chemical transformations. In contrast to their heme analogues, non-heme iron centers afford greater structural flexibility with important implications for their diverse catalytic mechanisms. We characterize an <i>in situ</i> structural model of the putative transient ferric intermediate of 2OG:taurine dioxygenase (TauD) by using a combination of spectroelectrochemical and semi-empirical computational methods, demonstrating that the Fe (III/II) transition involves a substantial, fully reversible, redox-linked conformational change at the active site. This rearrangement alters the apparent redox potential of the active site between -127 mV for reduction of the ferric state and 171 mV for oxidation of the ferrous state of the 2OG-Fe-TauD complex. Structural perturbations exhibit limited sensitivity to mediator concentrations and potential pulse duration. Similar changes were observed in the Fe-TauD and taurine-2OG-Fe-TauD complexes, thus attributing the reorganization to the protein moiety rather than the cosubstrates. Redox difference infrared spectra indicate a reorganization of the protein backbone in addition to the involvement of carboxylate and histidine ligands. Quantitative modeling of the transient redox response using two alternative reaction schemes across a variety of experimental conditions strongly supports the proposal for intrinsic protein reorganization as the origin of the experimental observations.

Evidence for the involvement of non-heme iron in the active site of hydrogenase from Desulfovibrio vulgaris

1971 ◽  
Vol 234 (3) ◽  
pp. 525-530 ◽  
Author(s):  
J. Legall ◽  
D.V. Dervartanian ◽  
E. Spilker ◽  
Jin-Po Lee ◽  
H.D. Peck
Keyword(s):  
Active Site ◽  
Heme Iron ◽  
Desulfovibrio Vulgaris ◽  
Non Heme Iron

scholarly journals Structural characterization of a non-heme iron active site in zeolites that hydroxylates methane

2018 ◽  
Vol 115 (18) ◽  
pp. 4565-4570 ◽  
Author(s):  
Benjamin E. R. Snyder ◽  
Lars H. Böttger ◽  
Max L. Bols ◽  
James J. Yan ◽  
Hannah M. Rhoda ◽  
...  
Keyword(s):  
Active Site ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Heme Iron ◽  
Zeolite Lattice ◽  
Non Heme Iron ◽  
Bonding Interaction ◽  
Lattice Density ◽  
X Ray Absorption

Iron-containing zeolites exhibit unprecedented reactivity in the low-temperature hydroxylation of methane to form methanol. Reactivity occurs at a mononuclear ferrous active site, α-Fe(II), that is activated by N2O to form the reactive intermediate α-O. This has been defined as an Fe(IV)=O species. Using nuclear resonance vibrational spectroscopy coupled to X-ray absorption spectroscopy, we probe the bonding interaction between the iron center, its zeolite lattice-derived ligands, and the reactive oxygen. α-O is found to contain an unusually strong Fe(IV)=O bond resulting from a constrained coordination geometry enforced by the zeolite lattice. Density functional theory calculations clarify how the experimentally determined geometric structure of the active site leads to an electronic structure that is highly activated to perform H-atom abstraction.

Computational Study of the Non-Heme Iron Active Site in Superoxide Reductase and Its Reaction with Superoxide

2003 ◽  
Vol 42 (2) ◽  
pp. 446-456 ◽  
Author(s):  
Radu Silaghi-Dumitrescu ◽  
Ioan Silaghi-Dumitrescu ◽  
Eric D. Coulter ◽  
Donald M. Kurtz
Keyword(s):  
Active Site ◽  
Computational Study ◽  
Heme Iron ◽  
Superoxide Reductase ◽  
Non Heme Iron

NMR studies of the active site of isopenicillin N synthase, a non-heme iron(II) enzyme

Biochemistry ◽  
1991 ◽  
Vol 30 (50) ◽  
pp. 11653-11659 ◽  
Author(s):  
Li June Ming ◽  
Lawrence Que ◽  
Aidas Kriauciunas ◽  
Charles A. Frolik ◽  
Victor J. Chen
Keyword(s):  
Active Site ◽  
Heme Iron ◽  
Nmr Studies ◽  
Non Heme Iron ◽  
Isopenicillin N

Spectroscopic definition of the non-heme iron active site in bleomycin

1995 ◽  
Vol 59 (2-3) ◽  
pp. 365
Author(s):  
Kelly E. Loeb ◽  
Jeffrey M. Zaleski ◽  
Tami E. Westre ◽  
Richard J. Guajardo ◽  
Pradip K. Mascharak ◽  
...  
Keyword(s):  
Active Site ◽  
Heme Iron ◽  
Non Heme Iron ◽  
Definition Of
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