al-Kazwini A T, Adams G E, O'Neill P, Naylor M A, Fielden E M
MRC Radiobiology Unit, Didcot, Oxon, United Kingdom.
Radiat Res. 1994 Jun;138(3):307-11.
The radiation-induced "in-pulse" luminescence emission from solid DNA containing either metronidazole or a highly electron-affinic 5-nitrofuran in the range 3-2000 (w:w) base pairs per additive molecule has been investigated in vacuo at 293 K using electron pulses of energy below 260 keV. The luminescence intensity at 450 nm from DNA decreases with increasing content of the additive in the sample and approaches a limiting level at high concentrations of the additives. At these higher concentrations the limiting value represents about 50% of that observed from DNA alone. It is shown that the efficiency of the additives in reducing the luminescence intensity is dependent upon their redox potential E1(7); this dependence is consistent with these additives acting as electron acceptors. It is concluded that the ability of the electron acceptors to reduce the luminescence is related to the electron affinity of E1(7) of the acceptors and electron migration distances of at least 300 base pairs are proposed.
利用能量低于260keV的电子脉冲，在293K真空中研究了含有甲硝唑或高电子亲和性5-硝基呋喃的固体DNA在3 - 2000（w:w）每添加剂分子碱基对范围内的辐射诱导“脉冲内”发光发射。样品中DNA在450nm处的发光强度随添加剂含量增加而降低，在高浓度添加剂时接近极限水平。在这些较高浓度下，极限值约为单独DNA所观察到值的50%。结果表明，添加剂降低发光强度的效率取决于它们的氧化还原电位E1(7)；这种依赖性与这些添加剂作为电子受体的作用一致。得出结论，电子受体降低发光的能力与受体的E1(7)电子亲和性有关，并提出电子迁移距离至少为300个碱基对。
