Characterization of radiation-induced damage in d(TpApCpG).
The radiation chemistry of the oligomer d(TpApCpG) X-irradiated in aqueous solution containing glutathione was studied. Four products were isolated by HPLC and characterized by NMR spectroscopy. Two of the major products are isomers of a 5-hydroxy-5,6-dihydrothymine modification of d(TpApCpG). A dihydrothymine modification is also formed. The other major product is a result of strand scission. These products are different from the major products identified previously in a study of d(TpApCpG) X-irradiated in oxygenated solution. The effect of specific radiation-induced lesions on the behaviour of d(TpApCpG) as substrate to a spleen phosphodiesterase-micrococcal nuclease combination of enzymes and to nuclease P1 was studied. These enzymes are of interest because they are used in postlabelling assays of DNA damage.
Paul
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CR
Department of Biophysics, Roswell Park Memorial Institute, Buffalo, New York 14263.
Budzinski
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EE
Maccubbin
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A
Wallace
J C
JC
Box
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HC
D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000528:radiation effects*; D004249:DNA Damage; D005092:Exonucleases; D005978:Glutathione; D009682:Magnetic Resonance Spectroscopy; D008836:Micrococcal Nuclease; D009838:Oligodeoxyribonucleotides / Q000528:radiation effects*; D015719:Single-Strand Specific DNA and RNA Endonucleases; D012996:Solutions; D014867:Water
D009838:Oligodeoxyribonucleotides; D012996:Solutions; D014867:Water; C066336:deoxy(thymidylic-adenylic-cytidylic-guanosine); D004247:DNA; D005092:Exonucleases; C022650:spleen exonuclease; D015719:Single-Strand Specific DNA and RNA Endonucleases; D008836:Micrococcal Nuclease; D005978:Glutathione