Formation and stability of acetaldehyde-induced crosslinks between poly-lysine and poly-deoxyguanosine.
The amino acid residue and nucleoside specificity of acetaldehyde-induced DNA-protein crosslinks (DPXLs) were studied using a modified filter binding assay. A 40% inhibition of acetaldehyde-induced pUC13 plasmid DNA-calf thymus histone crosslink formation was achieved by addition of 50 mM lysine (free base), while arginine was unable to affect crosslink formation at concentrations to 150 mM. Polymers (5-mers) of lysine (poly-lys5) were able to substitute for histones in acetaldehyde-induced plasmid crosslink formation, being equally effective at equimolar concentrations. Homopolymers (6-mers) of deoxyguanosine (poly-dG6) (but not deoxyadenosine, deoxycytidine or thymidine) served as an efficient substrate for acetaldehyde-induced DPXL formation, using either calf thymus histones or poly-lys5 as the protein source. Acetaldehyde-induced crosslinks between poly-dG6 and poly-lys5 were formed rapidly, but were unstable at 37 degrees C (a half-life or 1.5-2 h). Stability of these crosslinks was unaffected by pH at a range of 5.5-9.0 at 37 degrees C for 2 h. Results presented here suggest that unstable complexes of deoxyguanosine and lysine constitute a major portion of the DPXLs formed by acetaldehyde in vitro.
Kuykendall
J R
JR
Haskell Laboratory for Toxicology and Industrial Medicine, E.I. duPont de Nemours and Company, Newark, DE 19711.
Bogdanffy
M S
MS
D000079:Acetaldehyde / Q000737:chemistry*; D003432:Cross-Linking Reagents; D003849:Deoxyguanosine / Q000737:chemistry*; D007700:Kinetics; D011107:Polylysine / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry
D003432:Cross-Linking Reagents; D011108:Polymers; D011107:Polylysine; D003849:Deoxyguanosine; D000079:Acetaldehyde