Isolation and characterization of a microperoxidase-8 with a modified histidine axial ligand

Primus, Jean-Louis; Boeren, Sjef; Nielen, Michel W. F.; Vervoort, Jacques; Banci, Lucia; Rietjens, Ivonne M. C. M.

doi:10.1007/s00775-002-0373-z

Cited by 7 publications

(3 citation statements)

References 62 publications

(89 reference statements)

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“…Authentic standards for hydroxylated His products were not available. Oxidation of His in microperoxidase-8 by ·OH led to a +16 m / z shift that was attributed to the hydroxylation of the nitrogen at position δ1 on the imidazole ring . Oxidation of RNAse A (by 1 O 2 ) and an IgG1 monoclonal antibody also produced +16 m / z His products.…”

Section: Resultsmentioning

confidence: 99%

“…Oxidation of His in microperoxidase-8 by •OH led to a +16 m/z shift that was attributed to the hydroxylation of the nitrogen at position δ1 on the imidazole ring. 70 Oxidation of RNAse A (by 1 O 2 ) 71 and an IgG1 monoclonal antibody 72 also produced +16 m/z His products. In the former study, the mass shift occurred in the active site of the enzyme and was assigned to hydroxylation.…”

Section: The Effect Of Natural Organic Matter On Trp Transformation B...mentioning

confidence: 99%

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Peroxymonosulfate Oxidizes Amino Acids in Water without Activation

Ruiz

Yang

Lochbaum

et al. 2019

Environ. Sci. Technol.

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A variety of peptidic and proteinaceous contaminants (e.g., proteins, toxins, pathogens) present in the environment may pose risk to human health and wildlife. Peroxymonosulfate is a strong oxidant (E H 0 = 1.82 V for HSO5 –, the predominant species at environmental pH values) that may hold promise for the deactivation of proteinaceous contaminants. Relatively little quantitative information exists on the rates of peroxymonosulfate reactions with free amino acids. Here, we studied the oxidation of 19 of the 20 standard proteinogenic amino acids (all except cysteine) by peroxymonosulfate without explicit activation. Reaction half-lives at pH 7 ranged from milliseconds to hours. Amino acids possessing sulfur-containing, heteroaromatic, or substituted aromatic side chains were the most susceptible to oxidation by peroxymonosulfate, with rates of transformation decreasing in the order methionine > tryptophan > tyrosine > histidine. The rate of tryptophan oxidation did not decrease in the presence of an aquatic natural organic matter. Singlet oxygen resulting from peroxymonosulfate self-decomposition, while detected by electron paramagnetic resonance spectroscopy, was unlikely to be the principal reactive species. Our results demonstrate that peroxymonosulfate is capable of oxidizing 19 amino acids without explicit activation and that solvent-exposed methionine and tryptophan residues are likely initial targets of oxidation in peptides and proteins.

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Section: Resultsmentioning

confidence: 99%

Section: The Effect Of Natural Organic Matter On Trp Transformation B...mentioning

confidence: 99%

Peroxymonosulfate Oxidizes Amino Acids in Water without Activation

Ruiz

Yang

Lochbaum

et al. 2019

Environ. Sci. Technol.

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“…Hemin complexes are able to catalyze the oxidation of typical peroxidase substrates, such as phenolic compounds, in the presence of hydrogen peroxide, through a catalytic cycle which is similar to that of peroxidases and microperoxidases. [35][36][37][38][39][40][41][42][43][44][45] The oxidation of p-cresol to phenol coupling dimers with H 2 O 2 catalyzed by [( 2 L)Fe III ] + (1), [( 2 L)Fe III Cu II ] 3+ (2), or [( 1 L)Fe III ] + was studied through the initial rates method to neglect the significant inactivation undergone by the complexes during the reactions. The kinetics were investigated at pH 5.0, 7.0 and 9.0 under conditions in which the rates do not depend on the substrate concentration but are linearly dependent on [H 2 O 2 ].…”

Section: Peroxidase Activitymentioning

confidence: 99%

A new dinuclear heme-copper complex derived from functionalized protoporphyrin IX

et al. 2007

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A new biomimetic model for the heterodinuclear heme/copper center of respiratory oxidases is described. It is derived from iron(III) protoporphyrin IX by covalent attachment of a Gly-L-His-OMe residue to one propionic acid substituent and an amino-bis(benzimidazole) residue to the other propionic acid substituent of the porphyrin ring, yielding the Fe(III) complex 1, and subsequent addition of a copper(II) or copper(I) ion, according to needs. The fully oxidized Fe(III)/Cu(II) complex, 2, binds azide more strongly than 1, and likely contains azide bound as a bridging ligand between Fe(III) and Cu(II). The two metal centers also cooperate in the reaction with hydrogen peroxide, as the peroxide adducts obtained at low temperature for 1 and 2 display different optical features. Support to this interpretation comes from the investigation of the peroxidase activity of the complexes, where the activation of hydrogen peroxide has been studied through the phenol coupling reaction of p-cresol. Here the presence of Cu(II) improves the catalytic performance of complex 2 with respect to 1 at acidic pH, where the positive charge of the Cu(II) ion is useful to promote O-O bond cleavage of the iron-bound hydroperoxide, but it depresses the activity at basic pH because it can stabilize an intramolecular hydroxo bridge between Fe(III) and Cu(II). The reactivity to dioxygen of the reduced complexes has been studied at low temperature starting from the carbonyl adducts of the Fe(II) complex, 3, and Fe(II)/Cu(I) complex, 4. Also in this case the adducts derived from the Fe(II) and Fe(II)/Cu(I) complexes, that we formulate as Fe(III)-superoxo and Fe(III)/Cu(II)-peroxo exhibit slightly different spectral properties, showing that the copper center participates in a weak interaction with the dioxygen moiety.

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Reactivity study on microperoxidase-8

2003

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The catalytic activity of the microperoxidase-8/H(2)O(2) system toward tyramine and 3-(4-hydroxyphenyl)propionic acid has been determined in acetate buffer, pH 5.0. Operating with a strong excess of hydrogen peroxide, the rate-determining step of the reaction was substrate oxidation. Owing to the fast microperoxidase-8 degradation, only the very initial phase of the reactions were analyzed. The reaction rates follow a substrate saturation behavior, with turnover numbers [ k(cat)=26+/-1 s(-1) for 3-(4-hydroxyphenyl)propionic acid and k(cat)=22+/-1 s(-1) for tyramine] that were similar for the two substrates. In contrast, the K(M) values indicated a reduced affinity for the catalyst active species by the positively charged phenol, probably due to repulsive interaction with the protonated N-terminal microperoxidase-8 amino group. The reactivity of the catalyst active species was studied upon incubation of microperoxidase-8 with a small excess hydrogen peroxide, followed by reaction with the phenolic substrates. The kinetic analysis showed that more than two active species are accumulated. The species responsible for the faster reactions was present in solution as a minor fraction. The active intermediate which accumulated in a larger amount (intermediate III) has a reduced substrate oxidation activity. Comparison of this activity with the kinetic constants obtained under turnover experiments shows that intermediate III is not involved in the microperoxidase-8 catalytic cycle. The active species of the catalytic process are intermediates I and II, which in the absence of substrate rapidly convert to intermediate III.

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Isolation and characterization of a microperoxidase-8 with a modified histidine axial ligand

Cited by 7 publications

References 62 publications

Peroxymonosulfate Oxidizes Amino Acids in Water without Activation

Peroxymonosulfate Oxidizes Amino Acids in Water without Activation

A new dinuclear heme-copper complex derived from functionalized protoporphyrin IX

Reactivity study on microperoxidase-8

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