Barnes J P, Bernhard W A
Department of Biophysics, University of Rochester, New York 14642-8408, USA.
Radiat Res. 1995 Jul;143(1):85-92.
A series of single- and double-stranded oligodeoxynucleotides of adenine and thymine, 8 to 12 nucleotides in length, were one-electron-reduced at 10 K in a > 8 M LiCl/H2O glass. The Q-band electron paramagnetic resonance (EPR) spectra of these radicals show that thymine is the dominant trapping site for mobile electrons in these oligomers. The spectra of the reduced oligomers in the series pd(AnT10-n).pd(A10-nTn) with n = 5-->10 showed a trend which is interpreted as either an increase in the probability of trapping at an adenine base in tracks of adenine > 7 base pairs in length, or the presence of different protonated states of the one-electron-reduced bases due to the adoption of a different conformational state for longer tracks of adenine, or a combination of these two possibilities. Analysis of the trends in the EPR spectra of the radicals as a function of sequence using multicomponent analysis is presented.
一系列由腺嘌呤和胸腺嘧啶组成的单链和双链寡聚脱氧核苷酸，长度为8至12个核苷酸，在10 K下于> 8 M LiCl/H₂O玻璃中进行单电子还原。这些自由基的Q波段电子顺磁共振（EPR）光谱表明，胸腺嘧啶是这些寡聚物中移动电子的主要捕获位点。在n = 5→10的pd(AnT10 - n).pd(A10 - nTn)系列还原寡聚物的光谱显示出一种趋势，这被解释为要么在长度大于7个碱基对的腺嘌呤链中，在腺嘌呤碱基处捕获的概率增加，要么由于较长的腺嘌呤链采用了不同的构象状态，单电子还原碱基存在不同的质子化状态，或者是这两种可能性的组合。本文介绍了使用多组分分析对自由基EPR光谱随序列变化趋势的分析。
