Abstract
| Language | English |
|---|---|
| Pages | 235-242 |
| Number of pages | 8 |
| Journal | Radiation Research |
| Volume | 157 |
| Issue number | 3 |
| DOIs | |
| State | Published - 2002 |
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Reductive damage in directly ionized DNA : saturation of the C5-C6 bond of cytosine in d(CGCG)2 crystals. / Debije, M.G.; Close, D.M.; Bernhard, W.A.
In: Radiation Research, Vol. 157, No. 3, 2002, p. 235-242.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Reductive damage in directly ionized DNA : saturation of the C5-C6 bond of cytosine in d(CGCG)2 crystals
AU - Debije,M.G.
AU - Close,D.M.
AU - Bernhard,W.A.
PY - 2002
Y1 - 2002
N2 - Electron paramagnetic resonance (EPR) was used to study an oligodeoxynucleotide duplex of d(CGCG)2 that is known to crystallize in Z-form. After X irradiation at 4 K, EPR data were collected on single crystals and polycrystalline samples as a function of annealing temperature and dose. A radical produced by the net gain of a hydrogen atom at C6 and a proton at N3, Cyt(C6+H, N3+H+)+¿·, is identified. This radical had not been positively identified in polymeric DNA previously. The Cyt(C6+H, N3+H+)+¿· makes up about 4¿% of the total radical population at 4 K, increasing to about 10¿–¿15¿% after the DNA is annealed to 240 K. There appears to be neither an increase nor a decrease in the absolute concentration of Cyt(C6+H, N3+H+)+¿· upon annealing from 4 K to 240 K. Additionally, the presence of another radical, one due to the net gain of hydrogen at C5 of cytosine, the Cyt(C5+H)·, is implicated. Together, these two radicals appear to account for 60¿–¿80¿% of the reduced species in DNA that has been irradiated at 4 K and annealed to 240 K.
AB - Electron paramagnetic resonance (EPR) was used to study an oligodeoxynucleotide duplex of d(CGCG)2 that is known to crystallize in Z-form. After X irradiation at 4 K, EPR data were collected on single crystals and polycrystalline samples as a function of annealing temperature and dose. A radical produced by the net gain of a hydrogen atom at C6 and a proton at N3, Cyt(C6+H, N3+H+)+¿·, is identified. This radical had not been positively identified in polymeric DNA previously. The Cyt(C6+H, N3+H+)+¿· makes up about 4¿% of the total radical population at 4 K, increasing to about 10¿–¿15¿% after the DNA is annealed to 240 K. There appears to be neither an increase nor a decrease in the absolute concentration of Cyt(C6+H, N3+H+)+¿· upon annealing from 4 K to 240 K. Additionally, the presence of another radical, one due to the net gain of hydrogen at C5 of cytosine, the Cyt(C5+H)·, is implicated. Together, these two radicals appear to account for 60¿–¿80¿% of the reduced species in DNA that has been irradiated at 4 K and annealed to 240 K.
U2 - 10.1667/0033-7587(2002)157[0235:RDIDID]2.0.CO;2
DO - 10.1667/0033-7587(2002)157[0235:RDIDID]2.0.CO;2
M3 - Article
VL - 157
SP - 235
EP - 242
JO - Radiation Research
T2 - Radiation Research
JF - Radiation Research
SN - 1938-5404
IS - 3
ER -