KH(O2)CO2⋅H2O2—An Oxygen-Rich Salt of Monoperoxocarbonic Acid

Adam, Arnold; Mehta, Mathias

doi:10.1002/(sici)1521-3773(19980605)37:10<1387::aid-anie1387>3.3.co;2-v

Cited by 12 publications

(15 citation statements)

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“…To further test this possibility, we compared bicarbonate and peroxymonocarbonate docking into the hSod1 active site. The available crystallographic data for peroxymonocarbonate , bicarbonate , and hSod1 permitted docking of both anions into the active site of the enzyme (see the Experimental Procedures) (Figure ). Also, the carboxylate moiety of peroxymonocarbonate formed two hydrogen bonds with the side chain of the conserved arginine (Arg 143 ) residue, whereas bicarbonate formed only one hydrogen bond.…”

Section: Resultsmentioning

confidence: 99%

Peroxymonocarbonate and Carbonate Radical Displace the Hydroxyl-like Oxidant in the Sod1 Peroxidase Activity under Physiological Conditions

Medinas

Toledo

Cerchiaro

et al. 2009

Chem. Res. Toxicol.

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Despite being one of the most important antioxidant defenses, Cu,Zn-superoxide dismutase (Sod1) has been frequently associated with harmful effects, including neurotoxicity. This toxicity has been attributed to immature forms of Sod1 and extraneous catalytic activities. Among these, the ability of Sod1 to function as a peroxidase may be particularly relevant because it is increased in bicarbonate buffer and produces the reactive carbonate radical. Despite many studies, how this radical forms remains unknown. To address this question, we systematically studied hSod1 peroxidase activity in the presence of nitrite, formate, and bicarbonate-carbon dioxide. Kinetic analyses of hydrogen peroxide consumption and of nitrite, formate, and bicarbonate-carbon dioxide oxidation showed that the Sod1-bound hydroxyl-like oxidant functions in the presence of nitrite and formate. In the presence of bicarbonate-carbon dioxide, this oxidant is replaced by peroxymonocarbonate, which is then reduced to the carbonate radical. Peroxymonocarbonate intermediacy was evidenced by (13)C NMR experiments showing line broadening of its peak in the presence of Zn,ZnSod1. In agreement, peroxymonocarbonate was docked into the hSod1 active site, where it interacted with the conserved Arg(143). Also, a reaction between peroxymonocarbonate and Cu(I)Sod1 was demonstrated by stopped-flow experiments. Kinetic simulations indicated that peroxymonocarbonate is produced during Sod1 turnover and not in bulk solution. In the presence of bicarbonate-carbon dioxide, sustained hSod1-mediated oxidations occurred with low steady-state concentrations of hydrogen peroxide (4-10 microM). Thus, carbonate radical formation through peroxymonocarbonate may be a key event in Sod1-induced toxicity.

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Section: Resultsmentioning

confidence: 99%

Peroxymonocarbonate and Carbonate Radical Displace the Hydroxyl-like Oxidant in the Sod1 Peroxidase Activity under Physiological Conditions

Medinas

Toledo

Cerchiaro

et al. 2009

Chem. Res. Toxicol.

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“…Peroxymonocarbonate is an anionic peracid, a fast oxidant, with structure HOOCO 2 − . 145 Ho et al 146 reported the epoxidation of alkenes using Mn 2+ in the presence of H 2 O 2 is electrogenerated in situ in aqueous bicarbonate solutions. There are several other reports on epoxidation of alkenes using catalysts such as manganese meso-tetraphenylporphyrin complex, 147 MnSO 4 , 148 oxodiperoxo molybdenum complex [MoO(O 2 ) 2 (salox)] (salox = salicylaldoxime) mesoporous silica incorporated oxodiperoxo-8-hydroxyquinolinolato Mo 6+ , 149 polymer supported Mo-(CO) 6 , 150 and hexa-thiocyanatorhenate 151 in the presence of H 2 O 2 /NaHCO 3 .…”

Section: ■ Introductionmentioning

confidence: 99%

Liquid-Phase Epoxidation of Light Olefins over W and Nb Nanocatalysts

Yan

Zhang

Liu

et al. 2018

ACS Sustainable Chem. Eng.

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Epoxides are among the most important essential building blocks with wide downstream applications in the chemical industry. In this context, rational design of cost-effective catalysts is critical to achieve high atom efficiency during epoxidation processes. Therefore, in this perspective, recent research progress on heterogeneous W and Nb nanocatalysts for facile liquid-phase epoxidation will be critically reviewed in terms of catalyst synthesis, surface characterization and structure–function relationship. Furthermore, plausible mechanisms for liquid-phase epoxidation of ethylene, propylene, hexene, octene and other light olefins, as well as deactivation mechanism of W and Nb catalysts will be systematically discussed with the aim to provide insights into fundamental understanding on novel epoxidation chemistry and improving activity, selectivity, and stability nanocatalytic materials.

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“…The X-ray structure of peroxymonocarbonate shows a true hydroperoxide (30), and it has been structurally and kinetically characterized using 13 C NMR (28). Bicarbonate at physiological concentrations accelerates the reaction of H 2 O 2 with thiols, thioethers, amines, and other small molecules such as GSH and albumin via formation of peroxymonocarbonate (29,31,32).…”

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confidence: 99%

Bicarbonate is essential for protein-tyrosine phosphatase 1B (PTP1B) oxidation and cellular signaling through EGF-triggered phosphorylation cascades

Dagnell

Cheng

Rizvi

et al. 2019

Journal of Biological Chemistry

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Edited by Ruma BanerjeeProtein-tyrosine phosphatases (PTPs) counteract protein tyrosine phosphorylation and cooperate with receptor-tyrosine kinases in the regulation of cell signaling. PTPs need to undergo oxidative inhibition for activation of cellular cascades of protein-tyrosine kinase phosphorylation following growth factor stimulation. It has remained enigmatic how such oxidation can occur in the presence of potent cellular reducing systems. Here, using in vitro biochemical assays with purified, recombinant protein, along with experiments in the adenocarcinoma cell line A431, we discovered that bicarbonate, which reacts with H 2 O 2 to form the more reactive peroxymonocarbonate, potently facilitates H 2 O 2 -mediated PTP1B inactivation in the presence of thioredoxin reductase 1 (TrxR1), thioredoxin 1 (Trx1), and peroxiredoxin 2 (Prx2) together with NADPH. The cellular experiments revealed that intracellular bicarbonate proportionally dictates total protein phosphotyrosine levels obtained after stimulation with epidermal growth factor (EGF) and that bicarbonate levels directly correlate with the extent of PTP1B oxidation. In fact, EGF-induced cellular oxidation of PTP1B was completely dependent on the presence of bicarbonate. These results provide a plausible mechanism for PTP inactivation during cell signaling and explain long-standing observations that growth factor responses and protein phosphorylation cascades are intimately linked to the cellular acid-base balance.

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KH(O2)CO2⋅H2O2—An Oxygen-Rich Salt of Monoperoxocarbonic Acid

Cited by 12 publications

References 0 publications

Peroxymonocarbonate and Carbonate Radical Displace the Hydroxyl-like Oxidant in the Sod1 Peroxidase Activity under Physiological Conditions

Peroxymonocarbonate and Carbonate Radical Displace the Hydroxyl-like Oxidant in the Sod1 Peroxidase Activity under Physiological Conditions

Liquid-Phase Epoxidation of Light Olefins over W and Nb Nanocatalysts

Bicarbonate is essential for protein-tyrosine phosphatase 1B (PTP1B) oxidation and cellular signaling through EGF-triggered phosphorylation cascades

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