Mössbauer study of a bacterial cytochrome oxidase: cytochrome c1aa3 from Thermus thermophilus.

Kent, Thomas A.; Münck, Eckard; Dunham, William; Filter, W F; Findling, Karen L.; Yoshida, Tatsuro; Fee, James A.

doi:10.1016/s0021-9258(18)33536-1

Cited by 53 publications

(28 citation statements)

References 24 publications

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“…However, the 57 Fe a3 HS,3+ quadrupole splitting values are very sensitive to these factors. This explains that the observed Mössbauer spectra are broad, that the parameters are difficult to define precisely, and that many of the reported parameters are averaged values [33–35] . Our calculated versus the several reported experimentally defined 57 Fe a3 HS,3+ Mössbauer isomer shift and quadrupole splitting values are compared in Figure 5.…”

Section: Resultsmentioning

confidence: 96%

“…On the other hand, when the H 2 O molecule is much closer to the Cu B 2+ site (Fe a3 HS,3+ −H 2 O−Cu B 2+ (c)–(d)), the calculated Δ E Q (Fe a3 HS,3+ ) values for the F‐coupled state are much larger than the corresponding AF‐coupled state. The observed Δ E Q (Fe a3 HS,3+ ) exp values around 1.0 to 1.3 mm s −1 (see Table 1) [33–36] likely arise from the DNC structures in which the H 2 O molecule is much closer to the Cu B 2+ site and the Fe a3 HS,3+ and Cu B 2+ sites are F‐coupled (see Tables 2 and 3). Meanwhile, the observed Δ E Q (Fe a3 HS,3+ ) exp values around 0.7 mm s −1 probably come from the structures where the H 2 O molecule is close to the Fe a3 HS,3+ site (whether the Fe a3 HS,3+ and Cu B 2+ sites are F‐ or AF‐coupled), or from the structures where the H 2 O molecule is much closer to Cu B 2+ and the two metal sites are AF‐coupled.…”

Section: Resultsmentioning

confidence: 98%

“…This explains that the observed Mössbauer spectra are broad, that the parameters are difficult to define precisely, and that many of the reported parameters are averaged values. [33][34][35] Our calculated versus the several reported experimentally defined 57 HS,3 + ) exp values around 1.0 to 1.3 mm s À 1 (see Table 1) [33][34][35][36] likely arise from the DNC structures in which the H 2 O molecule is much closer to the Cu B 2 + site and the Fe a3 HS,3 + and Cu B 2 + sites are F-coupled (see Tables 2 and 3). Meanwhile, the observed ΔE Q (Fe a3 In Tt c 1 aa 3 and ba 3 at certain pH or at low temperature (see Table 1), [35,36] a "low-spin" Fe a3 3 + species was observed with δ = 0.29 mm s À 1 and ΔE Q = 2.21/2.24 mm s À 1 .…”

Section: Chemphyschemmentioning

confidence: 96%

“…Earlier 57 Fe Mössbauer experiments also demonstrated extensive structural and electronic heterogeneities in the DNC for the resting O state CcOs. [33][34][35][36] The major Mössbauer experimental observations on different CcOs are summarized in Table 1. Initial experiments on both Tt c 1 aa 3 and bovine aa 3 show broad 57 Fe a3 spectra with isomer shift (δ) and quadrupole splitting (ΔE Q ) values averaged at (δ = 0.41 mm s À 1 , ΔE Q = 1.10 mm s À 1 ) and (δ = 0.48 � 0.06 mm s À 1 , ΔE Q = 1.0 � 0.1 mm s À 1 ), respectively.…”

Section: Introductionmentioning

confidence: 99%

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DFT Calculations for Mössbauer Properties on Dinuclear Center Models of the Resting Oxidized Cytochrome c Oxidase

Götz

Noodleman

2022

ChemPhysChem

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Mössbauer isomer shift and quadrupole splitting properties have been calculated using the OLYP-D3(BJ) density functional method on previously obtained (W.-G. Han Du, et al., Inorg Chem. 2020, 59, 8906-8915) geometry optimized Fe a3 3 + À H 2 OÀ Cu B 2 + dinuclear center (DNC) clusters of the resting oxidized (O state) "as-isolated" cytochrome c oxidase (CcO). The calculated results are highly consistent with the available experimental observations. The calculations have also shown that the structural heterogeneities of the O state DNCs implicated by the Mössbauer experiments are likely consequences of various factors, particularly the variable positions of the central H 2 O molecule between the Fe a3 3 + and Cu B 2 + sites in different DNCs, whether or not this central H 2 O molecule has Hbonding interaction with another H 2 O molecule, the different spin states having similar energies for the Fe a3 3 + sites, and whether the Fe a3 3 + and Cu B 2 + sites are ferromagnetically or antiferromagnetically spin-coupled.

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Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 98%

Section: Chemphyschemmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

DFT Calculations for Mössbauer Properties on Dinuclear Center Models of the Resting Oxidized Cytochrome c Oxidase

Götz

Noodleman

2022

ChemPhysChem

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“…In the oxidized C c O, fast and slow forms are defined according to the rate of reaction of the enzyme with exogenous anionic ligands such as fluoride (F – ), cyanide (CN – ), and formate (HCOO – ). , Both forms of the enzyme have been proposed to consist of the Fe III –X–Cu II moiety, in which X represents a bridging ligand that modulates the coupling between two metal ions. , Naturally occurring X groups, which have been proposed, include oxide (O 2– ), hydroxide (OH – ), cyanide (CN – ), formate (HCOO – ), chloride (Cl – ), fluoride (F – ), and an imidazolate group . Mössbauer spectroscopic measurements of Paracoccus denitrificans and bovine heart C c O revealed that high-spin Fe 3+ ( S = 5/2) was strongly coupled with Cu 2+ ( S = 1/2), resulting in no EPR signal in the fast form of the enzyme. , However, in the slow form, the magnetic coupling and zero-field-splitting parameters are quantitatively different from those of the fast enzyme and result in the observation of an active EPR spectrum. ,, Dual-mode X-band EPR spectra of fluoride cytochrome bo 3 show broad, fast relaxing features with a similar pattern of bands: a weak derivative signal below 100 mT ( g ≈ 12) accompanied by a broad band in the 200–250 mT region ( g ≈ 3.2). ,− Simulations of dual-mode spectra indicated that the metal ions were weakly coupled by an anisotropic exchange interaction of | J | ≈ 1 cm –1 .…”

Section: Introductionmentioning

confidence: 99%

Intermolecular Interactions and Intramolecular Couplings of Binuclear Porphyrin Models for Cytochrome c Oxidase

et al. 2020

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Cytochrome c oxidase (CcO) has a binuclear active site composed of a high-spin heme group and a tris-histidine-ligated copper ion (CuB). By using two different porphyrin models derived by Gunter (H2TPyPP) and us (H2TImPP), we have isolated several mono- and binuclear complexes including one carbonyl and three chloride derivatives which are determined by 100 K single-crystal X-ray. Low-temperature (4 K) EPR and multitemperature (295–25 K) Mössbauer investigations on the products not only confirmed the spin states of the two metal ions (S = 5/2 Fe3+ and S = 1/2 Cu2+) but also revealed the intermolecular interactions and intramolecular couplings which are in accordance with the crystal structural features.

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Iron Porphyrin Chemistry

Walker¹,

Simonis²

2005

Encyclopedia of Inorganic Chemistry

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This article reviews most aspects of the chemistry of iron porphyrins, from Fe(0) to Fe(V), including occurrence and roles of natural iron porphyrins (hemes) and their synthetic analogs, structures and electron configurations of iron porphyrins of all oxidation and spin states, π electron configuration of the porphyrin ring, synthesis of metal‐free porphyrins and other related macrocycles, insertion of iron into free‐base porphyrins and related macrocycles, the properties, reactions, uses and biological relevance of iron(0), ‐(I), ‐(II) porphyrins (the latter with S = 0, 1, and 2 spin state possibilities), of iron(II) porphyrin π‐cation radicals, of iron(III) porphyrins (with S = 1/2, 3/2, and 5/2 spin state possibilities), of iron(III) porphyrin and corrole π‐cation radicals, of iron(IV) porphyrins (including five‐ and six‐coordinate ferryl (FeO) 2+ , iron(IV) phenyl, carbene and hydrazine complexes, and the bis‐methoxide complex) and a comparison of iron(IV) porphyrins to iron(III) porphyrin π‐cation radicals, of iron(IV) porphyrin π‐cation radicals, and of the possible existence of iron(V) porphyrins. Included in the Fe(II) part are sections on addition of ligands to four‐coordinate iron(II) porphyrins, including equilibrium binding constants, photodissociation of ligands from PFeL 2 complexes, binding of small molecules (O 2 , CO, NO, HNO) to 5‐coordinate iron(II) porphyrins and design of porphyrin ligands that will mimic the active sites of heme proteins such as myoglobin and hemoglobin, the cytochromes P450 and nitric oxide synthases, and the nitrophorins and guanylyl cyclases. Included in the iron(III) part are sections on both 5‐ and 6‐coordinate high‐spin complexes and their similarities and differences, bridged or through‐space magnetically coupled complexes of high‐spin iron(III) porphyrins with other metal complexes as possible models for cytochrome oxidase and the assimilatory sulfite reductases, coupled oxidation of hemes by hydrogen peroxide or its equivalent, and the relationship of this reactivity to the reactions of heme oxygenase, iron(III) porphyrins as reduction catalysts, and photochemistry of iron(III) porphyrins, possible electron configurations of low‐spin iron(III) porphyrins, the phenomenon and possible electronic consequences of ruffling of the porphinato core in iron(III) porphyrins, the preferred orientation of planar axial ligands bound to low‐spin iron(III) porphyrins, NO complexes of iron(III) porphyrins, reduction potentials, equilibrium constants and rates of axial‐ligand addition and exchange, kinetics of axial‐ligand rotation and porphyrin ring inversion, kinetics of reduction and autoreduction of iron(III) porphyrins, electron self‐exchange between low‐spin iron(III) and iron(II) porphyrins, synthetic ferriheme proteins, and synthesis of five‐coordinate low‐spin iron(III) porphyrins having σ‐alkyl or σ‐aryl groups as axial ligands. The iron(IV) and iron(IV) cation radical sections discuss the high‐valent states of cytochromes P450 and related enzymes.

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Mössbauer study of a bacterial cytochrome oxidase: cytochrome c1aa3 from Thermus thermophilus.

Cited by 53 publications

References 24 publications

DFT Calculations for Mössbauer Properties on Dinuclear Center Models of the Resting Oxidized Cytochrome c Oxidase

DFT Calculations for Mössbauer Properties on Dinuclear Center Models of the Resting Oxidized Cytochrome c Oxidase

Intermolecular Interactions and Intramolecular Couplings of Binuclear Porphyrin Models for Cytochrome c Oxidase

Iron Porphyrin Chemistry

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