Formation of DNA-protein cross-links between gamma-hydroxypropanodeoxyguanosine and EcoRI.
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.
VanderVeen
Laurie A
LA
A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
Harris
Thomas M
TM
Jen-Jacobson
Linda
L
Marnett
Lawrence J
LJ
D004247:DNA / Q000737:chemistry*; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000737:chemistry; D015246:Deoxyribonuclease EcoRI / Q000737:chemistry*; D015394:Molecular Structure; D013329:Structure-Activity Relationship; D013997:Time Factors
C488128:alpha-hydroxypropanodeoxyguanosine; D004247:DNA; D015246:Deoxyribonuclease EcoRI; D003849:Deoxyguanosine