Razskazovskiy Yuriy, Debije Michael G, Howerton Shelley B, Williams Loren D, Bernhard William A
Department of Biochemistry and Biophysics, University of Rochester, Rochester, New York 14642, USA.
Radiat Res. 2003 Sep;160(3):334-9. doi: 10.1667/rr3051.
Direct ionization of crystalline d(CGCGCGCG) and d(CGCGCGCGCG) oligomers produces 3'- and 5'-phosphate-terminated fragments as the main strand breakage products detectable by ion-exchange chromatography. The nature of the base has no effect on the probability of strand breakage at the given site. The yields of 3'-phosphates are systematically lower than the yields of the 5'-phosphates originating from the same cleavage site, pointing to the possible presence of unidentified products with sugar remnants attached to the 3'-end. These results show that direct ionization is efficient at producing single-strand breaks in DNA and its action is relatively indiscriminate with respect to base sequence.
结晶态的d(CGCGCGCG)和d(CGCGCGCGCG)寡聚物的直接电离产生3'-和5'-磷酸末端片段，这些片段是通过离子交换色谱法可检测到的主要链断裂产物。碱基的性质对给定位置处链断裂的概率没有影响。源自相同切割位点的3'-磷酸的产率系统地低于5'-磷酸的产率，这表明可能存在3'-末端附着有糖残基的未鉴定产物。这些结果表明，直接电离在DNA中产生单链断裂方面是有效的，并且其作用相对于碱基序列而言相对不加区分。
