Peroxymonosulfate Oxidizes Amino Acids in Water without Activation

Abstract

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.

Mn2O3 as an Electron Shuttle between Peroxymonosulfate and Organic Pollutants: The Dominant Role of Surface Reactive Mn(IV) Species

“…Results in Figure S5 show that the addition of FFA (1.0 mM) has no noticeable effect on the degradation of phenol, implying that 1 O 2 does not contribute to the phenol removal, although it is generated in the Mn 2 O 3 /PMS process. This result is consistent with previous reports. ,, Based on the above results, we conclude that the aqueous reactive species play a negligible role in the degradation of phenol in the Mn 2 O 3 /PMS process.…”

“…This result is consistent with previous reports. 13,57,58 Based on the above results, we conclude that the aqueous reactive species play a negligible role in the degradation of phenol in the Mn 2 O 3 /PMS process.…”

Fe–Fe Double-Atom Catalysts for Murine Coronavirus Disinfection: Nonradical Activation of Peroxides and Mechanisms of Virus Inactivation

“…Interestingly, the reactivity between these amino acids and PMS is low because PMS only reacts with sulfur-containing cysteine and methionine (Met) rapidly, and the reaction rate constant of Met–PMS is 3–6 orders of magnitude higher than those of other amino acids (Table S12). , In addition, Fe–Fe/SCN-activated PMS likely promoted catalyst-mediated electron transfer in which PMS directly abstracted electrons from organics mediated on Fe–Fe/SCN. , Therefore, it is reasonable not to see the apparent damage of virus binding after the oxidation by PMS-alone and Fe–Fe/SCN-activated PMS. After binding to the receptor, the putative fusion peptide (FP) and two heptad repeat regions (HR1 and HR2) in the S2 unit play a key role in coronavirus–cell membrane fusion. , In membrane fusion, FP is first inserted into the cell membrane, HR2 then binds to HR1 in an antiparallel manner to form a stable six-helix bundle, and the trimer-of-hairpins conformation brings both viral and cell membranes into close proximity (Figure a) .…”

“…Interestingly, the reactivity between these amino acids and PMS is low because PMS only reacts with sulfur-containing cysteine and methionine (Met) rapidly, and the reaction rate constant of Met−PMS is 3−6 orders of magnitude higher than those of other amino acids (Table S12). 63,64 In addition, Fe−Fe/SCNactivated PMS likely promoted catalyst-mediated electron transfer in which PMS directly abstracted electrons from organics mediated on Fe−Fe/SCN. 21,22 Therefore, it is reasonable not to see the apparent damage of virus binding after the oxidation by PMS-alone and Fe−Fe/SCN-activated PMS.…”

Synergistic Combination of Graphitic Carbon Nitride and Peroxymonosulfate for Efficient Photocatalytic Destruction of Emerging Contaminants under Simulated Solar Irradiation

“…In addition to the radicalrelated mechanism, a nonradical mechanism might also have participated in ARB inactivation. PMS is regarded as a versatile oxidative agent in water, and it has been used to achieve amino acid oxidation, 69 protein inactivation, 70 and DBP cytotoxicity reduction. 71 The oxidating PMS could facilitate the inactivation process of antibiotic resistance.…”