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Formation of DNA-protein cross-links between gamma-hydroxypropanodeoxyguanosine and EcoRI.

VanderVeen LA, Harris TM, Jen-Jacobson L, Marnett LJ - Chem. Res. Toxicol. (2008)

Bottom Line: Interestingly, the cross-link did not restrict the ability of EcoRI to cleave DNA substrates.However, stabilization of the cross-link by reduction of the Schiff base linkage resulted in loss of enzyme activity.Reversal of cross-link formation allows EcoRI to effect enzymatic cleavage of competitor oligonucleotides.

View Article: PubMed Central - PubMed

Affiliation: A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.

ABSTRACT
The toxicity of acrolein, an alpha,beta-unsaturated aldehyde produced during lipid peroxidation, is attributable to its high reactivity toward DNA and cellular proteins. The major acrolein-DNA adduct, gamma-hydroxypropano-2'-deoxyguanosine (gamma-HOPdG), ring opens to form a reactive N(2)-oxopropyl moiety that cross-links to DNA and proteins. We demonstrate the ability of gamma-HOPdG in a duplex oligonucleotide to cross-link to a protein (EcoRI) that specifically interacts with DNA at a unique sequence. The formation of a cross-link to EcoRI was dependent on the intimate binding of the enzyme to its gamma-HOPdG-modified recognition site. Interestingly, the cross-link did not restrict the ability of EcoRI to cleave DNA substrates. However, stabilization of the cross-link by reduction of the Schiff base linkage resulted in loss of enzyme activity. This work indicates that the gamma-HOPdG-EcoRI cross-link is in equilibrium with free oligonucleotide and enzyme. Reversal of cross-link formation allows EcoRI to effect enzymatic cleavage of competitor oligonucleotides.

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Structures of DNA adducts and their ring-opening products.
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fig1: Structures of DNA adducts and their ring-opening products.

Mentions: Acrolein is a mutagen and a tumor initiator produced endogenously via lipid peroxidation and myeloperoxidase-catalyzed amino acid oxidation (5−8). It is also an ubiquitous pollutant found in automobile exhaust and cigarette smoke (9). Acrolein exhibits facile reactivity with proteins (8) and represents a significant source of endogenous DNA damage by forming cyclic adducts with DNA bases and DNA−protein cross-links (10,11). The major products of the reaction of acrolein with DNA are exocyclic adducts of deoxyguanosine, (8R/S)-3-(2′-deoxyribos-1′-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2a]purin-10(3H)-one (γ-HOPdG)1 and (6R/S)-3-(2′-deoxyribos-1′-yl)-5,6,7,8-tetrahydro-6-hydroxypyrimido[1,2a]purin-10(3H)-one (α-HOPdG) (10) (Figure 1). α-HOPdG is more mutagenic than γ-HOPdG and induces G→T transversions in site-specific mutagenesis experiments (12). Both γ-HOPdG and α-HOPdG are present in human lung DNA at levels in excess of those typically reported for polycyclic aromatic hydrocarbon−DNA adducts (13).


Formation of DNA-protein cross-links between gamma-hydroxypropanodeoxyguanosine and EcoRI.

VanderVeen LA, Harris TM, Jen-Jacobson L, Marnett LJ - Chem. Res. Toxicol. (2008)

Structures of DNA adducts and their ring-opening products.
© Copyright Policy - open-access - ccc-price
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2651693&req=5

fig1: Structures of DNA adducts and their ring-opening products.
Mentions: Acrolein is a mutagen and a tumor initiator produced endogenously via lipid peroxidation and myeloperoxidase-catalyzed amino acid oxidation (5−8). It is also an ubiquitous pollutant found in automobile exhaust and cigarette smoke (9). Acrolein exhibits facile reactivity with proteins (8) and represents a significant source of endogenous DNA damage by forming cyclic adducts with DNA bases and DNA−protein cross-links (10,11). The major products of the reaction of acrolein with DNA are exocyclic adducts of deoxyguanosine, (8R/S)-3-(2′-deoxyribos-1′-yl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2a]purin-10(3H)-one (γ-HOPdG)1 and (6R/S)-3-(2′-deoxyribos-1′-yl)-5,6,7,8-tetrahydro-6-hydroxypyrimido[1,2a]purin-10(3H)-one (α-HOPdG) (10) (Figure 1). α-HOPdG is more mutagenic than γ-HOPdG and induces G→T transversions in site-specific mutagenesis experiments (12). Both γ-HOPdG and α-HOPdG are present in human lung DNA at levels in excess of those typically reported for polycyclic aromatic hydrocarbon−DNA adducts (13).

Bottom Line: Interestingly, the cross-link did not restrict the ability of EcoRI to cleave DNA substrates.However, stabilization of the cross-link by reduction of the Schiff base linkage resulted in loss of enzyme activity.Reversal of cross-link formation allows EcoRI to effect enzymatic cleavage of competitor oligonucleotides.

View Article: PubMed Central - PubMed

Affiliation: A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.

ABSTRACT
The toxicity of acrolein, an alpha,beta-unsaturated aldehyde produced during lipid peroxidation, is attributable to its high reactivity toward DNA and cellular proteins. The major acrolein-DNA adduct, gamma-hydroxypropano-2'-deoxyguanosine (gamma-HOPdG), ring opens to form a reactive N(2)-oxopropyl moiety that cross-links to DNA and proteins. We demonstrate the ability of gamma-HOPdG in a duplex oligonucleotide to cross-link to a protein (EcoRI) that specifically interacts with DNA at a unique sequence. The formation of a cross-link to EcoRI was dependent on the intimate binding of the enzyme to its gamma-HOPdG-modified recognition site. Interestingly, the cross-link did not restrict the ability of EcoRI to cleave DNA substrates. However, stabilization of the cross-link by reduction of the Schiff base linkage resulted in loss of enzyme activity. This work indicates that the gamma-HOPdG-EcoRI cross-link is in equilibrium with free oligonucleotide and enzyme. Reversal of cross-link formation allows EcoRI to effect enzymatic cleavage of competitor oligonucleotides.

Show MeSH
Related in: MedlinePlus