The metal-catalyzed oxidation of methionine in peptides by Fenton systems involves two consecutive one-electron oxidation processes

Hong, Jinyang; Schöneich, Christian

doi:10.1016/s0891-5849(01)00722-5

Cited by 48 publications

(51 citation statements)

References 45 publications

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“…According to the latter hypothesis, Ab generates hydrogen peroxide from molecular oxygen through electron transfer interactions involving bound redox-active metal ion (Curtain et al, 2001;Huang et al, 1999). Hydrogen peroxide is readily converted to a highly reactive hydroxyl radical by Fenton reaction and both forms may be responsible for some of the oxidative damage observed during post-mortem examination of AD patient's brain tissue (Hong and Schoneich, 2001;Rival et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Silibinin: A novel inhibitor of Aβ aggregation

Yin

Liu

Ji³

et al. 2011

Neurochemistry International

117

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Section: Discussionmentioning

confidence: 99%

Silibinin: A novel inhibitor of Aβ aggregation

Yin

Liu

Ji³

et al. 2011

Neurochemistry International

117

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“…We propose that this reaction may follow the paradigm for aromatic ring extradiol dioxygenases (26), including substrate coordination, binding and activation of O 2 , and then substrate oxidation. Owing to the ability of sulfur to access cation-radical intermediates (27,28), this reaction may not require the assistance of an additional redox cofactor such as the Tyr-157-Cys-93 adduct.…”

Section: Discussionmentioning

confidence: 99%

“…One consequence of formation of the Fe(III)-superoxo intermediate (Fig. 5D) would be to increase the cation-radical character of sulfur (27,28), which would promote recombination with Fe(III)-superoxo to form a cyclic peroxo intermediate (Fig. 5E).…”

Section: Discussionmentioning

confidence: 99%

Structure and mechanism of mouse cysteine dioxygenase

McCoy

Bailey

Bitto

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

188

238

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Cysteine dioxygenase (CDO) catalyzes the oxidation of L-cysteine to cysteine sulfinic acid. Deficiencies in this enzyme have been linked to autoimmune diseases and neurological disorders. The x-ray crystal structure of CDO from Mus musculus was solved to a nominal resolution of 1.75 Å. The sequence is 91% identical to that of a human homolog. The structure reveals that CDO adopts the typical ␤-barrel fold of the cupin superfamily. The NE2 atoms of His-86, -88, and -140 provide the metal binding site. The structure further revealed a covalent linkage between the side chains of Cys-93 and Tyr-157, the cysteine of which is conserved only in eukaryotic proteins. Metal analysis showed that the recombinant enzyme contained a mixture of iron, nickel, and zinc, with increased iron content associated with increased catalytic activity. Details of the predicted active site are used to present and discuss a plausible mechanism of action for the enzyme.cupin ͉ cysteine metabolism ͉ O2-activation M ouse cysteine dioxygenase (CDO) catalyzes the initial step in the biochemical pathway used for oxidation of cysteine to sulfate (1), namely the oxidation of L-cysteine to cysteine sulfinic acid as shown in Fig. 1. The enzyme activity has important medical implications because elevated cysteine levels have been associated with Parkinson's and Alzheimer's diseases (2). High cysteine-to-sulfate ratios have been observed in patients suffering from systemic lupus erthematosus and rheumatoid arthritis (3, 4). Moreover, the Hallervorden-Spatz syndrome, a neurological disorder associated with iron accumulation, has been linked to a decline in CDO activity (5).CDO displays significant sequence identity with some members of the cupin superfamily (6), which have a conserved ␤-barrel fold and share two conserved sequence motifs: G(X) 5 HXH(X) 3,4 E(X) 6 G and G(X) 5 PXG(X) 2 H(X) 3 N (6-8).The two His and Glu residues from the first motif and the His from the second motif coordinate the metal ion in germin, the superfamily archetype (9). The Mus musculus CDO sequence contains the first motif with the exception of the glutamate, which is replaced by cysteine. This substitution is conserved in other eukaryotic CDOs. The second motif is less conserved, and only the His and Asn residues are present in the mouse CDO.CDO does not require an external reductant ( Fig. 1) and incorporates both oxygen atoms from O 2 (10), which justifies the dioxygenase classification, but relatively little else is known about the reaction mechanism. The recombinant enzyme from Rattus norvegicus has been purified and characterized by steadystate kinetics (11); the mouse enzyme investigated here has an identical sequence. Reconstitution of the rat apoenzyme with various transition metals confirmed that iron was required for activity, in accord with the earlier conclusions (1). Moreover, the recombinant rat enzyme was active without a second interacting factor, despite previous reports suggesting that additional components were required (12, 13).Here, we describe the x-ra...

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“…The ROS reagents were prepared according to the method described in the literature (Hong and Schöneich, 2001;Dufield et al, 2004). In a plastic tube, 0.25 mM CCK8 and 60 mM H 2 O 2 were mixed in the volume ratio of 9:1(v/v) so that the final concentrations of CCK8 and H 2 O 2 were 0.17 and 5 mM, respectively.…”

Section: Oxidation Of Cck8 By Rosmentioning

confidence: 99%

Analysis of oxidation process of cholecystokinin octapeptide with reactive oxygen species by high‐performance liquid chromatography and subsequent electrospray ionization mass spectrometry

Ichiba¹,

Nakamoto²,

Yajima³

et al. 2009

Biomedical Chromatography

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The C-terminal octapeptide of cholecystokinin (CCK8) includes some easily oxidizable amino acids. The oxidation of CCK8 by reactive oxygen species (ROS) such as hydrogen peroxide (H(2)O(2)) and hydroxyl radicals (OH(*)) was investigated using reversed-phase high performance liquid chromatography (RP-HPLC) and subsequent electrospray ionization mass spectrometry. The mechanism of oxidation of CCK8 in the H(2)O(2) system differed from that of CCK8 in the Fenton system, in which OH(*) are produced. In the H(2)O(2) system, (28)Met and (31)Met were oxidized to methionine sulfoxide, and no further oxidation or degradation/hydrolysis occurred. On the other hand, in the Fenton system, (28)Met and (31)Met residues were oxidized to methionine sulfone via the formation of methionine sulfoxide. In addition, the oxidized product was observed at the Trp residue but not at the Tyr residue, and small peptide fragments from CCK8 were observed in the Fenton system. From these results, it was concluded that (28)Met and (31)Met residues of CCK8 are susceptible to oxidation by ROS.

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The metal-catalyzed oxidation of methionine in peptides by Fenton systems involves two consecutive one-electron oxidation processes

Cited by 48 publications

References 45 publications

Silibinin: A novel inhibitor of Aβ aggregation

Silibinin: A novel inhibitor of Aβ aggregation

Structure and mechanism of mouse cysteine dioxygenase

Analysis of oxidation process of cholecystokinin octapeptide with reactive oxygen species by high‐performance liquid chromatography and subsequent electrospray ionization mass spectrometry

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