Redox Biology (Feb 2024)

Identification of sulfhydryl-containing proteins and further evaluation of the selenium-tagged redox homeostasis-regulating proteins

  • Zhongyao Jiang,
  • Yue Tang,
  • Jun Lu,
  • Chang Xu,
  • Yaxin Niu,
  • Guanglu Zhang,
  • Yanmei Yang,
  • Xiufen Cheng,
  • Lili Tong,
  • Zhenzhen Chen,
  • Bo Tang

Journal volume & issue
Vol. 69
p. 102969

Abstract

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Chemoproteomic profiling of sulfhydryl-containing proteins has consistently been an attractive research hotspot. However, there remains a dearth of probes that are specifically designed for sulfhydryl-containing proteins, possessing sufficient reactivity, specificity, distinctive isotopic signature, as well as efficient labeling and evaluation capabilities for proteins implicated in the regulation of redox homeostasis. Here, the specific selenium-containing probes (Se-probes) in this work displayed high specificity and reactivity toward cysteine thiols on small molecules, peptides and purified proteins and showed very good competitive effect of proteins labeling in gel-ABPP. We identified more than 6000 candidate proteins. In TOP-ABPP, we investigated the peptide labeled by Se-probes, which revealed a distinct isotopic envelope pattern of selenium in both the primary and secondary mass spectra. This unique pattern can provide compelling evidence for identifying redox regulatory proteins and other target peptides. Furthermore, our examiation of post-translational modification (PTMs) of the cysteine site residues showed that oxidation PTMs was predominantly observed. We anticipate that Se-probes will enable broader and deeper proteome-wide profiling of sulfhydryl-containing proteins, provide an ideal tool for focusing on proteins that regulate redox homeostasis and advance the development of innovative selenium-based pharmaceuticals.

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