Products from polycrystalline DNA constituents after X-irradiation and heavy-ion bombardment: Formation of the 5,6-dihydroadduct in thymidine 5'-monophosphate and release of unaltered bases in nucleotides
| Autor: | A.-K. Hoffmann, J. Hüttermann |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Guanine
Magnetic Resonance Spectroscopy Oligonucleotides Analytical chemistry Mass spectrometry Cytosine DNA Adducts chemistry.chemical_compound Thymidine Monophosphate Heavy Ions Radiology Nuclear Medicine and imaging Nucleotide Irradiation Chromatography High Pressure Liquid chemistry.chemical_classification Thymidine monophosphate Radiological and Ultrasound Technology Chemistry Oligonucleotide Adenine X-Rays Radiochemistry X-ray Dose-Response Relationship Radiation DNA Models Chemical Thymidine |
| Zdroj: | International Journal of Radiation Biology. 76:1167-1178 |
| ISSN: | 1362-3095 0955-3002 |
| DOI: | 10.1080/09553000050134401 |
| Popis: | The major products from polycrystalline purine and pyrimidine DNA nucleotides after low- and high-LET irradiation were investigated quantitatively by HPLC and 1H-NMR spectroscopy.Solid nucleotide samples were either X-irradiated as cylindrical pellets or heavy-ion bombarded (LET range of 100-12,500 keV/microm) as very thin tablets at 300K. Product analysis was performed by HPLC and 1H-NMR.For TMP the 5,6-dihydroadduct was found to be formed as product of electron reaction. In addition, all four DNA nucleotides showed a radiation-induced base release, which is probably connected with the oxidative radiation action. The formation of the products was linear with dose up to 300 kGy for X-irradiation or 200 kGy for heavy-ion bombardment. The estimation of the radiation chemical yields revealed G-values of about 10(-7) mol x J(-1) and were typically smaller for irradiation with charged particles than those for X-rays. After heavy-ion bombardment the G-values first increased with increasing LET and decreased for very heavy ions.The yields for base release from both purine and pyrimidine nucleotides are comparable in magnitude. The 5,6-dihydroadduct from TMP is a major radiation induced product with larger yields than found for base release after X-irradiation and comparable yields after heavy-ion bombardment. The LET dependence of the G-values for base release in nucleotides is similar and resembles the double strand break formation in DNA. The observed similarity in the LET dependence of the G-values might derive from an inhomogeneous distribution of energy deposition resulting in 'clustered damage'. |
| Databáze: | OpenAIRE |
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