Cysteine occupies a central position in plant metabolism because it is a reduced sulfur donor molecule involved in the synthesis of essential biomolecules and defense compounds. Moreover, cysteine per se and its derivative molecules play roles in the redox signaling of processes occurring in various cellular compartments. Cysteine is synthesized during the sulfate assimilation pathway via the i...

In an accompanying paper (Kennedy, M. C., Spoto, G., Emptage, M. H., and Beinert, H. (1988) J. Biol. Chem. 263, 8190-8193), it was shown that one cysteine per mol of aconitase is modified by a variety of sulfhydryl reagents. We have identified the tryptic peptide that contains the iodoacetamide-reactive cysteine. We have also demonstrated that this cysteine is the primary site of modification b...

Oxygen free radicals produced by neutrophils are important in the pathogenesis of mucosal damage in ulcerative colitis. Vitamin A, vitamin E and cysteine in the plasma can scavenge free radicals. In the present study, plasma levels of vitamin A, vitamin E, cysteine, cystine and protein-bound cysteine were measured in active ulcerative colitis before and immediately after treatment of the active...

l-Cysteine is a semi-essential amino acid and substrate for cystathionine-β-synthase (CBS) in the central nervous system. We previously reported that NaHS, an H2S donor, significantly alleviated brain damage after subarachnoid hemorrhage (SAH) in rats. However, the potential therapeutic value of l-cysteine and the molecular mechanism supporting these beneficial effects have not been determined....

We used a newly developed procedure to determine reduced, oxidized, and protein-bound forms of homocysteine, cysteine, cysteinylglycine, and glutathione to measure the plasma concentrations of these species during methionine loading in six young healthy men with normal fasting concentrations of plasma homocysteine and cysteine. The methionine loading induced a transient increase in total homocy...