Download MendeleyStructural and Mechanistic Characterization of Mycobacterium tuberculosis TrxR Inhibition by Glutathione-Coated Gold Nanocluster.
Li, Z., Niu, W., Xia, D., Chen, Y., Chen, S., Zhang, B., Wang, J., Zhu, H., Yang, H., Xie, F., Zhou, Y., Gong, Y., Xu, Y., Cao, P.(2026) Int J Mol Sci 27
- PubMed: 41683636
- DOI: https://doi.org/10.3390/ijms27031209
- Primary Citation of Related Structures:
9XUB - PubMed Abstract:
Mycobacterium tuberculosis ( M. tuberculosis ) relies on the thioredoxin (Trx)-thioredoxin reductase (TrxR) system to maintain intracellular redox homeostasis and to support Trx-dependent DNA synthesis and repair, making TrxR a potential target for anti-tuberculosis therapy. Gold nanoclusters have been reported to inhibit human TrxR and suppress tumor growth, suggesting that gold-based nanomaterials can modulate TrxR activity. In this study, we report a previously uncharacterized oxidized crystal structure of M. tuberculosis TrxR containing two dimers in the asymmetric unit and use this structure to investigate inhibition by a glutathione-coated gold nanocluster (GSH-AuNC). Biolayer interferometry and enzymatic assays show that GSH-AuNC binds directly to M. tuberculosis TrxR and efficiently inhibits its catalytic activity at the purified enzyme level. Molecular dynamics simulations indicate that GSH-AuNC can occupy a surface pocket proximal to the active site, providing a plausible structural basis for enzyme engagement. AlphaFold3 modeling of the M. tuberculosis TrxR-Trx heterodimeric complex defines the interaction interface required for productive electron transfer and provides a structural hypothesis for how GSH-AuNC disrupts this process. Together, these results provide structural and mechanistic insights into the biochemical modulation of M. tuberculosis TrxR by GSH-AuNC, while the antimycobacterial activity of GSH-AuNC remains to be evaluated in future studies.
- Beijing Key Laboratory of Cardiopulmonary-Cerebral Resuscitation Innovation and Translation, College of Chemistry and Life Science, Beijing University of Technology, Beijing 100124, China.
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