Protein S-thiolation in hepatocytes stimulated by t-butyl hydroperoxide, menadione, and neutrophils

Arch Biochem Biophys. 1994 Apr;310(1):264-72. doi: 10.1006/abbi.1994.1166.

Abstract

In order to examine potentially important S-thiolated proteins, 35S-labeled hepatocytes were exposed to oxidative stress. A similar group of S-thiolated proteins including carbonic anhydrase III was observed in cells treated with t-butyl hydroperoxide, menadione, or stimulated neutrophils. The radioactive thiols bound to hepatocyte proteins were identified by HPLC and more than 85% was glutathione. In menadione-treated hepatocytes, proteins were gradually S-thiolated over 30 min and 25% of the cellular glutathione pool became protein-bound. In t-butyl hydroperoxide-treated cells, S-thiolation was more transient and 11% of the glutathione was protein-bound. Neutrophil-treated hepatocytes had nearly the same amount of protein S-thiolation (8% after 25 min). Two major proteins that were S-thiolated in untreated hepatocytes did not increase during any form of oxidative stress. In neutrophil-treated hepatocytes protein S-thiolation was not accompanied by either formation of glutathione disulfide or a measurable change in the total amount of glutathione. In both t-butyl hydroperoxide-and menadione-treated cells there was extensive formation of glutathione disulfide and in menadione-treated cells a significant increase in the total hepatocyte glutathione pool was observed. This result suggests that protein S-thiolation may occur by mechanisms that do not result from thiol/disulfide exchange between glutathione disulfide and protein sulfhydryls. It is suggested that a thiyl radical intermediate is important in neutrophil-mediated protein S-thiolation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbonic Anhydrases / metabolism
  • Disulfides / metabolism*
  • Glutathione / metabolism
  • Liver / cytology
  • Liver / drug effects
  • Liver / metabolism*
  • Male
  • Neutrophils / metabolism
  • Peroxides / pharmacology
  • Proteins / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Sulfhydryl Compounds / metabolism*
  • Vitamin K / pharmacology
  • tert-Butylhydroperoxide

Substances

  • Disulfides
  • Peroxides
  • Proteins
  • Sulfhydryl Compounds
  • Vitamin K
  • tert-Butylhydroperoxide
  • Carbonic Anhydrases
  • Glutathione