Physical exercise induces oxidation of plasma protein thiols to cysteine mixed disulfides in humans

Takayo Inayama*, Misato Kashiba, Jun Oka, Mitsuru Higuchi, Keizo Umegaki, Makoto Saito, Yorihiro Yamamoto, Mitsuo Matsuda

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


We have reported that strenuous physical exercise causes a decrease in protein-bound sulfhydryl groups (p-SHs), such as albumin cysteine residues, in human plasma (Inayama et al., 1996, Life Sci., 59, 573-578). We further investigated the fate of plasma protein thiols after moderate exercise. Six untrained healthy female volunteers ran for 30-min at the individual ventilatory threshold. We observed an increase in protein cysteine mixed disulfides (p-S-Cys) after running, as evidenced by reducing plasma proteins with dithiothreitol to detect the increase of cysteine, along with the concomitant decrease in p-SHs in plasma. However, plasma protein-bound glutathione (GSH) and S-nitroso-protein were undetectable before and after exercise. Test tube experiments suggest that p-S-Cys are probably formed by the hydrolysis of protein GSH mixed disulfides by γ-glutamyltranspeptidase and peptidase, and/or by the oxidative addition of p-SHs to cystine.

Original languageEnglish
Pages (from-to)399-403
Number of pages5
JournalJournal of Health Science
Issue number5
Publication statusPublished - 2002 Oct
Externally publishedYes


  • Cysteine mixed disulfide
  • Human
  • Physical exercise
  • Plasma protein thiol

ASJC Scopus subject areas

  • Toxicology
  • Health, Toxicology and Mutagenesis


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