Unveiling the Molecular Basis of Silver(I) Sequestration by Glutathione: Stoichiometry, Stability and Structure at Neutral pH
5 affiliations
- 1Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, Warsaw, Poland, 02-106
- 2Doctoral School of Molecular Biology and Biological Chemistry
- 3IBB PAS
- 4Université de Pau et des Pays de l’Adour, 2 Av. du Président Pierre Angot, Pau, France
- 5NanoBioMedical Centre, Adam Mickiewicz University, Wszechnicy Piastowskiej 3, Poznań, Poland, 61-614
Abstract
The complexation of Ag(I) ions by reduced glutathione (GSH) at neutral pH was studied by UV-vis, CD and NMR spectroscopies and mass spectrometry, aided by DFT calculations. A tetrameric Ag 4 (GSH) 4 complex was found to be the sole species at these conditions, containing the octagonal Ag 4 S 4 ring with digonal S-Ag-S coordination mode. The pH-independent stability constant of this complex was determined by competitive titrations with excess of thiosulfate ions as KAg4(GSH)4 = 1.6 × 10 67 M -7 . Equilibrium calculations using this constant indicate that physiological millimolar GSH concentrations can sequester all substoichiometric Ag(I) ions, presumably preventing their toxicity towards cellular proteins. However, the ring structure of the complex is not compatible with the standard cellular heavy metal detoxication mechanism. These results provide a molecular basis for deciphering the role of glutathione in cellular silver toxicity and detoxication.
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BibTeX
@misc{szczerba2026unveiling,
title = {{Unveiling the Molecular Basis of Silver(I) Sequestration by Glutathione: Stoichiometry, Stability and Structure at Neutral pH}},
author = {Paulina Szczerba and Tshering Zangmo and Luisa Ronga and Joanna Szpunar and Kosma Szutkowski and Igor Zhukov and Wojciech Bal},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15010809/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010809/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Unveiling the Molecular Basis of Silver(I) Sequestration by Glutathione: Stoichiometry, Stability and Structure at Neutral pH
AU - Paulina Szczerba
AU - Tshering Zangmo
AU - Luisa Ronga
AU - Joanna Szpunar
AU - Kosma Szutkowski
AU - Igor Zhukov
AU - Wojciech Bal
PY - 2026
DA - 2026/10/21
PB - ChemRxiv
DO - 10.26434/chemrxiv.15010809/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15010809/v1
AB - The complexation of Ag(I) ions by reduced glutathione (GSH) at neutral pH was studied by UV-vis, CD and NMR spectroscopies and mass spectrometry, aided by DFT calculations. A tetrameric Ag 4 (GSH) 4 complex was found to be the sole species at these conditions, containing the octagonal Ag 4 S 4 ring with digonal S-Ag-S coordination mode. The pH-independent stability constant of this complex was determined by competitive titrations with excess of thiosulfate ions as KAg4(GSH)4 = 1.6 × 10 67 M -7 . Equilibrium calculations using this constant indicate that physiological millimolar GSH concentrations can sequester all substoichiometric Ag(I) ions, presumably preventing their toxicity towards cellular proteins. However, the ring structure of the complex is not compatible with the standard cellular heavy metal detoxication mechanism. These results provide a molecular basis for deciphering the role of glutathione in cellular silver toxicity and detoxication.
ER -