N‐Acetylcysteine as a chemical scavenger for sulfur mustard: New insights by mass spectrometry

Siegert, Markus; Kranawetvogl, Andreas; Thiermann, Horst; John, Harald

doi:10.1002/dta.2299

Cited by 9 publications

(4 citation statements)

References 37 publications

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“…Most recently, SM was used by the terrorist group islamic state of Iraq and the Levant (ISIL) in Syria and Northern Iraq, 3–6 and accidental exposures have also been reported, 7,8 thus underlining the need to understand the pathophysiology, to develop appropriate antidotes, and to establish analytical methods for biomedical verification of poisoning. Once SM enters the bloodstream, it forms adducts with various molecules by alkylation of, for example, proteins, DNA, hormones, glutathione, and N ‐acetylcysteine 9–14 . Human serum albumin (HSA) is a well‐known target of SM being alkylated at diverse amino acid residues including cysteine 34 (Cys 34 ) 3,8,14–16 .…”

Section: Introductionmentioning

confidence: 99%

Identification of creatine kinase and alpha‐1 antitrypsin as protein targets of alkylation by sulfur mustard

Lüling

Schmeißer²,

Siegert

et al. 2020

Drug Testing and Analysis

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Sulfur mustard (SM) is a toxic chemical warfare agent deployed in several conflicts within the last 100 years and still represents a threat in terroristic attacks and warfare. SM research focuses on understanding the pathophysiology of SM and identifying novel biomarkers of exposure. SM is known to alkylate nucleophilic moieties of endogenous proteins, for example, free thiol groups of cysteine residues. The two‐dimensional‐thiol‐differences in gel electrophoresis (2D‐thiol‐DIGE) technique is an initial proteomics approach to detect proteins with free cysteine residues. These amino acids are selectively labeled with infrared‐maleimide dyes visualized after GE. Cysteine residues derivatized by alkylating agents are no longer accessible for the maleimide–thiol coupling resulting in the loss of the fluorescent signal of the corresponding protein. To prove the applicability of 2D‐thiol‐DIGE, this technology was exemplarily applied to neat human serum albumin treated with SM, to lysates from human cell culture exposed to SM as well as to human plasma exposed to CEES (chloroethyl ethyl sulfide, an SM analogue). Exemplarily, the most prominent proteins modified by SM were identified by matrix‐assisted laser desorption/ionization time‐of‐flight (tandem) mass spectrometry, MALDI‐TOF MS(/MS), as creatine kinase (CK) from human cells and as alpha‐1 antitrypsin (A1AT) from plasma samples. Peptides containing the residue Cys282 of CK and Cys232 of A1AT were unambiguously identified by micro liquid chromatography‐electrospray ionization high‐resolution tandem‐mass spectrometry (μLC‐ESI MS/HR MS) as being alkylated by SM bearing the specific hydroxyethylthioethyl‐(HETE)‐moiety. Both peptides might represent potential biomarkers of SM exposure. This is the first report introducing these endogenous proteins as targets of SM alkylation.

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Section: Introductionmentioning

confidence: 99%

Identification of creatine kinase and alpha‐1 antitrypsin as protein targets of alkylation by sulfur mustard

Lüling

Schmeißer²,

Siegert

et al. 2020

Drug Testing and Analysis

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“…This peptide also derived from pepsin-mediated cleavage and contains the Cys 34 -residue. It could be excluded, that the increasing amounts of LQQC(-HETE)PFED were produced by the reaction with remaining SM as under reaction conditions applied, SM should have been hydrolyzed completely within the first 30 minutes (period of half-change in PBS: 3.9 minutes) 25. More likely, the additional alkylation of Cys 34 was due to the nucleophilic attack of the free thiol-group to the Cα next to the sulfonium sulfur atom of the HETE moiety of the alkylated Met 329 .The regeneration of Met by the nucleophilic attack of a thiol group is Long-term stability of alkylated Met 329 in human serum.…”

mentioning

confidence: 99%

Methionine³²⁹ in human serum albumin: A novel target for alkylation by sulfur mustard

Siegert

Gandor

Kranawetvogl

et al. 2019

Drug Testing and Analysis

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Exposure to the vesicant sulfur mustard (SM) may lead to erythema and blistering.Toxicity of SM is hypothesized due to the alkylation of DNA bases and nucleophilic amino acid side chains in proteins (adducts) by forming the hydroxyethylthioethyl (HETE) moiety. Despite its prohibition by the chemical weapons convention, SM still represents a serious threat to military personnel and civilians. Therefore, development and improvement of forensic analytical methods for the verification of SM exposure is of high interest. Protein adducts have been shown to be highly suitable and beneficial biomarkers of poisoning. Herein we present methionine 329 in human serum albumin (HSA) as a novel target of SM forming a HETE-methionyl sulfonium ion.The alkylated tetrapeptide LeuGlyMet 329 (-HETE)Phe, LGM(-HETE)F, was detected after pepsin-mediated proteolysis and subsequent analysis by microbore liquid chromatography-electrospray ionization-high-resolution tandem-mass spectrometry.Compound identity was confirmed by a synthetic reference. Proteolysis conditions for HSA were optimized towards maximum yield of LGM(-HETE)F and its limit of identification (32.3 nM SM in serum) was similar to those of the established HSA-derived biomarkers HETE-CysPro and HETE-CysProPhe (15.6 nM SM in serum).Stability of the alkylated Met 329 in vitro and in vivo was limited to 5 days making this modification a beneficial short-time biomarker. Furthermore, it was found that the HETE-methionyl sulfonium ion can transfer its HETE moiety to the side chain of cysteine and glutamic acid as well as to the N-terminus of peptides and proteins in vitro thus revealing novel insights into the molecular toxicity of SM.

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“…No correlations were made with cellular viability in these studies, although it was concluded that chemical scavenging of H by NAC was not the major route through which these effects occurred [ 71 ], a conclusion later supported by mass spectrometric studies where NAC and H were co-incubated in either phosphate buffered saline or human serum. In this work, although reaction products of NAC and H were detected and identified, “analyses clearly documented minor reactivity not significantly contributing to reduction of SM concentrations” [ 72 ].…”

Section: Nac and Sulphur Mustardmentioning

confidence: 99%

N-Acetylcysteine as a treatment for sulphur mustard poisoning

Sawyer

2020

Free Radical Biology and Medicine

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In the long and intensive search for effective treatments to counteract the toxicity of the chemical warfare (CW) agent sulphur mustard (H; bis(2-chloroethyl) sulphide), the most auspicious and consistent results have been obtained with the drug N-acetylcysteine (NAC), particularly with respect to its therapeutic use against the effects of inhaled H. It is a synthetic cysteine derivative that has been used in a wide variety of clinical applications for decades and a wealth of information exists on its safety and protective properties against a broad range of toxicants and disease states. Its primary mechanism of action is as a pro-drug for the synthesis of the antioxidant glutathione (GSH), particularly in those circumstances where oxidative stress has exhausted intracellular GSH stores. It impacts a number of pathways either directly or through its GSH-related antioxidant and anti-inflammatory properties, which make it a prime candidate as a potential treatment for the wide range of deleterious cellular effects that H is acknowledged to cause in exposed individuals. This report reviews the available literature on the protection afforded by NAC against the toxicity of H in a variety of model systems, including its efficacy in treating the long-term chronic lung effects of H that have been demonstrated in Iranian veterans exposed during the Iran-Iraq War (1980-1988). Although there is overwhelming evidence supporting this drug as a potential medical countermeasure against this CW agent, there is a requirement for carefully controlled clinical trials to determine the safety, efficacy and optimal NAC dosage regimens for the treatment of inhaled H.

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N‐Acetylcysteine as a chemical scavenger for sulfur mustard: New insights by mass spectrometry

Cited by 9 publications

References 37 publications

Identification of creatine kinase and alpha‐1 antitrypsin as protein targets of alkylation by sulfur mustard

Identification of creatine kinase and alpha‐1 antitrypsin as protein targets of alkylation by sulfur mustard

Methionine³²⁹ in human serum albumin: A novel target for alkylation by sulfur mustard

N-Acetylcysteine as a treatment for sulphur mustard poisoning

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N‐Acetylcysteine as a chemical scavenger for sulfur mustard: New insights by mass spectrometry

Cited by 9 publications

References 37 publications

Identification of creatine kinase and alpha‐1 antitrypsin as protein targets of alkylation by sulfur mustard

Identification of creatine kinase and alpha‐1 antitrypsin as protein targets of alkylation by sulfur mustard

Methionine329 in human serum albumin: A novel target for alkylation by sulfur mustard

N-Acetylcysteine as a treatment for sulphur mustard poisoning

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Methionine³²⁹ in human serum albumin: A novel target for alkylation by sulfur mustard