Genest D, Wahl P
Biochim Biophys Acta. 1978 Dec 21;521(2):502-9. doi: 10.1016/0005-2787(78)90292-7.
The transient fluorescence of solutions of ethidium bromide . DNA complexes has been measured by pulse fluorimetry at different temperatures and in solvents containing various amounts of sucrose. The molar ratio of ethidium to nucleotides was low. Under these conditions the anisotropy decay was due to the Brownian motion of ethidium molecules intercalated in the double strand DNA molecules. This anisotropy decay could be described by a sum of 3 exponential terms, with correlation times 01, 02, 03 which were linear functions of the ratio of the solvent viscosity to the absolute temperature (n/T). The amplitude of the exponential term characterized by the shortest correlation time (01) has been found to depend on temperature while the ratio of the amplitude of the two other terms (characterized by 02 and 03) was independent of temperature. These results were interpreted as follows: 01 corresponds to a fast motion of the dye in its site. 02 and 03 describe a tortional motion of the ethidium bromide. DNA complex, involving several nucleotide pairs.
已通过脉冲荧光法在不同温度下以及在含有不同量蔗糖的溶剂中测量了溴化乙锭 - DNA复合物溶液的瞬态荧光。溴化乙锭与核苷酸的摩尔比很低。在这些条件下，各向异性衰减是由于插入双链DNA分子中的溴化乙锭分子的布朗运动所致。这种各向异性衰减可用3个指数项的和来描述，其相关时间τ1、τ2、τ3是溶剂粘度与绝对温度之比（η/T）的线性函数。已发现以最短相关时间（τ1）为特征的指数项的幅度取决于温度，而其他两个项（以τ2和τ3为特征）的幅度之比与温度无关。这些结果的解释如下：τ1对应于染料在其位点的快速运动。τ2和τ3描述了溴化乙锭 - DNA复合物的扭转运动，涉及几个核苷酸对。
