Antimicrobial silver targets glyceraldehyde-3-phosphate dehydrogenase in glycolysis of E. coli

• Published in: Chemical science (Cambridge) 2019-08, Vol.10 (30), p.7193-7199
• Main Authors: Wang, Haibo, Wang, Minji, Yang, Xinming, Xu, Xiaohan, Hao, Quan, Yan, Aixin, Hu, Menglong, Lobinski, Ryszard, Li, Hongyan, Sun, Hongzhe
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Antiinfectives and antibacterials; Catalysis; Chemical Sciences; Coupling; Coupling (molecular); E coli; Electrophoresis; Enzymes; Glycolysis; Inductively coupled plasma mass spectrometry; Mass spectrometry; Material chemistry; or physical chemistry; Organic chemistry; Polymers; Proteins; Silver; Theoretical and
• ISSN: 2041-6520; 2041-6539
• DOI: 10.1039/c9sc02032b

Silver has long been used as an antibacterial agent, yet its molecular targets remain largely unknown. Using a custom-designed coupling of gel electrophoresis with inductively coupled plasma mass spectrometry (GE-ICP-MS), we identified six silver-binding proteins in . The majority of the identified proteins are associated with the central carbon metabolism of . Among them, we unveil that GAPDH, an essential enzyme in glycolysis, serves as a vital target of Ag in for the first time. We demonstrate that silver inhibits the enzymatic function of GAPDH through targeting Cys149 in its catalytic site. The X-ray structure reveals that Ag coordinates to Cys149 and His176 with a quasi-linear geometry (S-Ag-N angle of 157°). And unexpectedly, two Ag ions coordinate to Cys288 in the non-catalytic site with weak argentophilic interaction (Ag···Ag distance of 2.9 Å). This is the first report on antimicrobial Ag targeting a key enzyme in the glycolytic pathway of . The findings expand our knowledge on the mode of action and bio-coordination chemistry of silver, particularly silver-targeting residues in proteins at the atomic level.