The effect of cyst(e)ine on the auto-oxidation of homocysteine

Free Radic Biol Med. 1999 Jul;27(1-2):28-33. doi: 10.1016/s0891-5849(99)00029-5.

Abstract

This study examines the effect of cysteine on the auto-oxidation of homocysteine, a process that has been implicated in the pathologic mechanism of hyperhomocystinemia with respect to arteriosclerosis and vascular disease. It is shown that homocysteine autoxidizes at a much slower rate than cysteine, but that low concentrations of cysteine or cystine dramatically accelerate homocysteine oxidation and increase the rate of homocysteine-dependent oxygen consumption. It is proposed that the major role of homocysteine is to reduce cystine to cysteine, and that cysteine autoxidation is the mechanism by which thiol-dependent oxidative stress occurs.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cysteine / chemistry*
  • Cystine / chemistry*
  • Glutathione / chemistry
  • Homocysteine / chemistry*
  • Oxidation-Reduction

Substances

  • Homocysteine
  • Cystine
  • Glutathione
  • Cysteine