title: Characterization of the deoxyguanosine-lysine cross-link of methylglyoxal.
abstract: Methylglyoxal is a mutagenic bis-electrophile that is produced endogenously from carbohydrate precursors. Methylglyoxal has been reported to induce DNA-protein cross-links (DPCs) in vitro and in cultured cells. Previous work suggests that these cross-links are formed between guanine and either lysine or cysteine side chains. However, the chemical nature of the methylglyoxal induced DPC have not been determined. We have examined the reaction of methylglyoxal, deoxyguanosine (dGuo), and Nα-acetyllysine (AcLys) and determined the structure of the cross-link to be the N2-ethyl-1-carboxamide with the lysine side chain amino group (1). The cross-link was identified by mass spectrometry and the structure confirmed by comparison to a synthetic sample. Further, the cross-link between methylglyoxal, dGuo, and a peptide (AcAVAGKAGAR) was also characterized. The mechanism of cross-link formation is likely to involve an Amadori rearrangement.
authors.affiliation: Departments of Chemistry and Biochemistry, Center in Molecular Toxicology, and Vanderbilt-Ingram Cancer Center, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors.forename: Katya V
authors.initials: KV
authors.lastname: Petrova
authors.forename: Amy D
authors.initials: AD
authors.lastname: Millsap
authors.forename: Donald F
authors.initials: DF
authors.lastname: Stec
authors.forename: Carmelo J
authors.initials: CJ
authors.lastname: Rizzo
mesh_terms: D003432:Cross-Linking Reagents / Q000737:chemistry*; D003849:Deoxyguanosine / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry*; D015394:Molecular Structure; D011765:Pyruvaldehyde / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003432:Cross-Linking Reagents; D011765:Pyruvaldehyde; D003849:Deoxyguanosine; D008239:Lysine