Structural characterization of verdoheme analogs. Iron complexes of octaethyloxoporphyrin

Balch, Alan L.; Latos‐Grażyński, Lechosław; Noll, Bruce C.; Olmstead, Marilyn M.; Szterenberg, Ludmiła; Safari, Nasser

doi:10.1021/ja00057a027

Cited by 80 publications

(84 citation statements)

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“…Two resonance structures have been suggested for verdoheme and are shown in Scheme 2 (29). Structure 4 possesses a positive charge on the ring oxygen atom, whereas the charge is on the iron atom in structure 3.…”

Section: Resultsmentioning

confidence: 99%

The Oxygen and Carbon Monoxide Reactions of Heme Oxygenase

Migita

Matera

Ikeda‐Saito

et al. 1998

Journal of Biological Chemistry

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The O 2 and CO reactions with the heme, ␣-hydroxyheme, and verdoheme complexes of heme oxygenase have been studied. and protein residues in the heme pocket. The CO affinities estimated for both isoforms are only 1-6-fold higher than the corresponding O 2 affinities. Thus, heme oxygenase discriminates much more strongly against CO binding than either myoglobin or hemoglobin. The CO binding reactions with the ferrous ␣-hydroxyheme complex are similar to those of the protoheme complex, and hydroxylation at the ␣-meso position does not appear to affect the reactivity of the iron atom. In contrast, the CO affinities of the verdoheme complexes are >10,000 times weaker than those of the heme complexes because of a 100-fold slower association rate constant (k CO Ϸ 0.004 M ؊1 s ؊1) and a 300-fold greater dissociation rate constant (k CO Ϸ 3 s ؊1 ) compared with the corresponding rate constants of the protoheme and ␣-hydroxyheme complexes. The positive charge on the verdoporphyrin ring causes a large decrease in reactivity of the iron.

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Section: Resultsmentioning

confidence: 99%

The Oxygen and Carbon Monoxide Reactions of Heme Oxygenase

Migita

Matera

Ikeda‐Saito

et al. 1998

Journal of Biological Chemistry

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“…Excess verdoheme was removed by passing the complex down a Sephadex G25 column equilibrated with CO-saturated potassium phosphate (pH 7.4). Formation and authenticity of the complex was confirmed by UV/Vis absorption spectroscopy, using the spectral data from Balch et al as the standard [44].…”

Section: Formation and Crystallization Of Verdoheme-ho-1 Complexmentioning

confidence: 99%

Crystal structures of ferrous and ferrous–NO forms of verdoheme in a complex with human heme oxygenase-1: catalytic implications for heme cleavage

Lad

Montellano

Poulos

2004

Journal of Inorganic Biochemistry

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“…[13,14] Chemical oxidation involving a variety of reagents [e.g., H 2 O 2 in pyridine, [15] cerium(IV) and thallium(III) salts [16] ] and a cou-pled oxidation of porphyrin complexes of redox active metals have been involved in the model investigations of heme degradation. [17] Porphyrin ring-opening reactions followed by photooxidation afforded oligopyrrole linear compounds. [18] Formylbiliverdins (3) and biliverdins (formed by extrusion of CO) are typically produced in degradation of meso unsubstituted porphyrins.…”

Section: Introductionmentioning

confidence: 99%

Photooxidation of Dithiaethyneporphyrin

Berlicka¹,

Latos‐Grażyński²,

Szterenberg³

et al. 2010

Eur J Org Chem

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The oxidative degradation of the contracted carbaporphyrinoid 3,8,13,18-tetraphenyldithiaethyneporphyrin, which contains an acetylene moiety embedded in the macrocyclic framework, was investigated. The light-induced, regioselective cleavage of the macrocyclic ring was observed during exposure to dioxygen affording four open-chain diastereomers terminated by carbonyl groups. Studies on the regioselectivity of the process showed that the thiophene was cleft together with the 8-aryl substituent, which proved the primary attack of dioxygen at the C8-C9 bond. Diastereomers {4Z,10E}, {4Z,10Z}, {4E,10E}, and {4E,10Z} [the arrangement with respect to C4-C5 and C10···C13 conjugated bonds given] differ by the orientation of the terminal pyrro-

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Structural characterization of verdoheme analogs. Iron complexes of octaethyloxoporphyrin

Cited by 80 publications

References 0 publications

The Oxygen and Carbon Monoxide Reactions of Heme Oxygenase

The Oxygen and Carbon Monoxide Reactions of Heme Oxygenase

Crystal structures of ferrous and ferrous–NO forms of verdoheme in a complex with human heme oxygenase-1: catalytic implications for heme cleavage

Photooxidation of Dithiaethyneporphyrin

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