Send to

Choose Destination
Arch Biochem Biophys. 2006 Jun 1;450(1):1-8. Epub 2006 Mar 22.

S-(2-Succinyl)cysteine: a novel chemical modification of tissue proteins by a Krebs cycle intermediate.

Author information

Department of Chemistry and Biochemistry, University of South Carolina, USA.


S-(2-Succinyl)cysteine (2SC) has been identified as a chemical modification in plasma proteins, in the non-mercaptalbumin fraction of human plasma albumin, in human skin collagen, and in rat skeletal muscle proteins and urine. 2SC increases in human skin collagen with age and is increased in muscle protein of diabetic vs. control rats. The concentration of 2SC in skin collagen and muscle protein correlated strongly with that of the advanced glycation/lipoxidation end-product (AGE/ALE), N(epsilon)-(carboxymethyl)lysine (CML). 2SC is formed by a Michael addition reaction of cysteine sulfhydryl groups with fumarate at physiological pH. Fumarate, but not succinate, inactivates the sulfhydryl enzyme, glyceraldehyde-3-phosphate dehydrogenase in vitro, in concert with formation of 2SC. 2SC is the first example of spontaneous chemical modification of protein by a metabolic intermediate in the Krebs cycle. These observations identify fumarate as an endogenous electrophile and suggest a role for fumarate in regulation of metabolism.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center