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Geometric and electronic structure/function correlations in non-heme iron enzymes.
TLDR
A detailed molecular mechanism has been proposed for IPNS based on spectroscopic and crystallographic studies and the role of cosubstrate ascorbate is proposed to reduce the toxic peroxo byproduct to water. Expand
Characterization of the [2Fe-2S] cluster of Escherichia coli transcription factor IscR.
TLDR
Characterization of anaerobically isolated IscR using resonance Raman, Mössbauer, and nuclear magnetic resonance spectroscopies leads to the proposal that the [2Fe-2S] cluster does not have full cysteinyl ligation, and Mutagenesis studies indicate that the highly conserved His107 residue is essential for cluster ligation. Expand
Characterization of the nitrosyl adduct of substrate-bound mouse cysteine dioxygenase by electron paramagnetic resonance: electronic structure of the active site and mechanistic implications.
TLDR
The unusual {FeNO}7 (S = 1/2) electronic configuration adopted by the substrate-bound iron-nitrosyl CDO (termed {ES-NO}) is a result of the bidentate thiol/amine coordination of l-cysteine in the NO-bound CDO active site, reflecting the high substrate specificity of the enzyme observed by a number of researchers. Expand
Comparison and contrasts between the active site PKs of Mn-superoxide dismutase and those of Fe-superoxide dismutase.
TLDR
It is shown that the pH dependence of Escherichia coli MnSOD activity reflects a different active site proton equilibrium in (oxidized) Mn(3+)SOD than the event that affects the active site pK of oxidized FeSOD. Expand
Nature of the peroxo intermediate of the W48F/D84E ribonucleotide reductase variant: implications for O2 activation by binuclear non-heme iron enzymes.
TLDR
This study provides significant insight into the electronic structure and reactivity of the R2-W48F/D84E peroxo intermediate, structurally related cis mu-1,2 peroxe model complexes, and other enzymatic biferric peroxi intermediates. Expand
How can a single second sphere amino acid substitution cause reduction midpoint potential changes of hundreds of millivolts?
TLDR
The hypothesis that the protein matrix can apply significant redox tuning via its influence over redox-coupled proton transfer and the energy associated with it is supported. Expand
Spectroscopic and computational characterization of substrate-bound mouse cysteine dioxygenase: nature of the ferrous and ferric cysteine adducts and mechanistic implications.
TLDR
Resting and substrate-bound forms of CDO in the Fe(II) and Fe(III) states were characterized by utilizing various spectroscopic methods and provide support for a reaction mechanism similar to that established for many structurally related 2-His-1-carboxylate Fe( II)-dependent dioxygenases. Expand
Spectroscopic and computational studies of Ni superoxide dismutase: electronic structure contributions to enzymatic function.
TLDR
Comparison of the computational results for NiSOD(red) with those obtained in parallel studies of synthetic [NiS(2)N(2)] complexes reveals that the presence of an anionic N-donor ligand is crucial for promoting metal-based (versus S-based) oxidation of the active site. Expand
Spectroscopic evidence for the formation of a four-coordinate Co2+ cobalamin species upon binding to the human ATP:cobalamin adenosyltransferase.
TLDR
The magnetic circular dichroism and electron paramagnetic resonance spectroscopic studies reported here reveal that, in the absence of ATP, the interaction between Co2+Cbl and hATR promotes partial conversion of the cofactor to its "base-off" form in which a water molecule occupies the lower axial position. Expand
Mechanism of alcohol oxidation mediated by copper(II) and nitroxyl radicals.
TLDR
The resulting Oppenauer-like reaction pathway further explains experimental trends in the relative reactivity of different classes of alcohols, as well as the different reactivity observed between TEMPO and bicyclic nitroxyls, such as ABNO. Expand
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