Efficiency of DNA-histone crosslinking induced by saturated and unsaturated aldehydes in vitro. |
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Authors: | J R Kuykendall M S Bogdanffy |
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Affiliation: | Haskell Laboratory for Toxicology and Industrial Medicine, E.I. du Pont de Nemours and Company, Newark, DE 19714. |
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Abstract: | Using a filter-binding assay based on precipitation of pUC13 plasmid DNA bound to calf-thymus histones, we have determined the efficiency of formation of DNA-protein crosslink formation induced by several aldehyde compounds in vitro. Formaldehyde, glutaraldehyde and acrolein were the most potent, causing 1 crosslink per 2.7 kbp of DNA at 1.5, 8 and 150 microM, respectively. All other compounds tested gave 1 crosslink per plasmid molecule in the mM concentration range as follows: acetaldehyde, 115 mM; propionaldehyde, 295 mM; butyraldehyde, 360 mM; crotonaldehyde, 8.5 mM; trans-2-pentenal, 6.3 mM. Significant decreases in the efficiency of DPXL formation were observed with monofunctional aldehydes of higher carbon chain length. For example, the concentration of formaldehyde needed to give 1 crosslink per molecule was almost 10(5) times less than that of acetaldehyde. Acetaldehyde differs from formaldehyde only by one saturated carbon. The presence of an unsaturated bond between the 2-3 carbons improved the potential for crosslink formation. For example, acrolein was over 500-fold more potent than propionaldehyde. Glutaraldehyde was almost as potent as formaldehyde, indicating that the bifunctional nature of this 5-carbon saturated aldehyde may be crucial to its high efficiency of DNA-protein crosslinking. |
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