title: S-(2-Succinyl)cysteine: a novel chemical modification of tissue proteins by a Krebs cycle intermediate.
abstract: 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.
authors.affiliation: Department of Chemistry and Biochemistry, University of South Carolina, USA.
authors.forename: Nathan L
authors.initials: NL
authors.lastname: Alderson
authors.forename: Yuping
authors.initials: Y
authors.lastname: Wang
authors.forename: Matthew
authors.initials: M
authors.lastname: Blatnik
authors.forename: Norma
authors.initials: N
authors.lastname: Frizzell
authors.forename: Michael D
authors.initials: MD
authors.lastname: Walla
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Lyons
authors.forename: Nadja
authors.initials: N
authors.lastname: Alt
authors.forename: James A
authors.initials: JA
authors.lastname: Carson
authors.forename: Ryoji
authors.initials: R
authors.lastname: Nagai
authors.forename: Suzanne R
authors.initials: SR
authors.lastname: Thorpe
authors.forename: John W
authors.initials: JW
authors.lastname: Baynes
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology; D002952:Citric Acid Cycle / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D003545:Cysteine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D005260:Female; D005650:Fumarates / Q000494:pharmacology; D017127:Glycation End Products, Advanced / Q000032:analysis / Q000378:metabolism*; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000032:analysis / Q000378:metabolism; D049528:Insulin, Long-Acting; D061386:Insulin, Regular, Human; D009124:Muscle Proteins / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000502:physiology*; D011837:Radiation-Protective Agents / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012709:Serum Albumin / Q000032:analysis / Q000378:metabolism; D000075462:Serum Albumin, Human; D012867:Skin / Q000378:metabolism; D019802:Succinic Acid / Q000494:pharmacology
chemical_list: C499251:Albulin; D016588:Anticarcinogenic Agents; D005650:Fumarates; D017127:Glycation End Products, Advanced; D007328:Insulin; D049528:Insulin, Long-Acting; D061386:Insulin, Regular, Human; D009124:Muscle Proteins; D011837:Radiation-Protective Agents; C511650:S-(2-succinyl)cysteine; D012709:Serum Albumin; C032005:fumaric acid; D003094:Collagen; D019802:Succinic Acid; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D003545:Cysteine; D000075462:Serum Albumin, Human