Targeting the Thioredoxin Reductase-Thioredoxin System from Staphylococcus aureus by Silver Ions

Xiangwen Liao, Fang Yang, Hongyan Li, Pui Kin So, Zhongping Yao, Wei Xia, Hongzhe Sun

Research output: Journal article publicationJournal articleAcademic researchpeer-review

14 Citations (Scopus)

Abstract

The thioredoxin system, which is composed of NADPH, thioredoxin reductase (TrxR), and thioredoxin (Trx), is one of the major disulfide reductase systems used by bacteria against oxidative stress. In particular, this reductase system is crucial for the survival of the pathogenic bacterium Staphylococcus aureus, which lacks a natural glutathione/glutaredoxin (Grx) system. Although silver ions and silver-containing materials have been used as antibacterial agents for centuries, the antibacterial mechanism of silver is not well-understood. Herein, we demonstrate that silver ions bind to the active sites of S. aureus TrxR and Trx with dissociation constants of 1.4 ± 0.1 μM and 15.0 ± 5.0 μM and stoichiometries of 1 and 2 Ag+ions per protein, respectively. Importantly, silver ion binding leads to oligomerization and functional disruption of TrxR as well as Trx. Silver also depleted intracellular thiol levels in S. aureus, disrupting bacterial thiol-redox homeostasis. Our study provides new insights into the antibacterial mechanism of silver ions. Moreover, the Trx and TrxR system might serve as a feasible target for the design of antibacterial drugs.
Original languageEnglish
Pages (from-to)14823-14830
Number of pages8
JournalInorganic Chemistry
Volume56
Issue number24
DOIs
Publication statusPublished - 18 Dec 2017

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Inorganic Chemistry

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