Dougherty G
J Math Biol. 1982;15(3):275-91. doi: 10.1007/BF00275688.
The optical linear dichroism of DNA-drug fibres and films can provide valuable information on the geometry of the binding and its extent, especially when used in conjunction with X-ray diffraction data from the same specimens. We have considered the macroscopic orientation of the helices within a fibre or film to be characterized by a Gaussian distribution of the helix axes about the fibre (or film) axis. Using this model we have obtained analytical expressions for the dichroic ratio without resorting to computer simulation techniques or numerical integration methods, and used them to interpret the results of experiments using DNA-phenanthridine fibres. As the humidity is increased, ethidium and dimidium bromide show an increased fraction of binding perpendicular to the helix axis, consistent with intercalation. Prothidium shows little preferred orientation in its binding, and the occurrence of a significant proportion of intercalation can be excluded.
DNA-药物纤维和薄膜的光学线性二色性可以提供有关结合几何结构及其程度的有价值信息，特别是当与来自相同样本的X射线衍射数据结合使用时。我们认为纤维或薄膜内螺旋的宏观取向由螺旋轴围绕纤维（或薄膜）轴的高斯分布来表征。使用该模型，我们在不借助计算机模拟技术或数值积分方法的情况下获得了二色性比率的解析表达式，并使用它们来解释使用DNA-菲啶纤维的实验结果。随着湿度增加，溴化乙锭和溴化二乙锭显示出垂直于螺旋轴的结合比例增加，这与嵌入作用一致。原黄素在其结合中几乎没有优先取向，并且可以排除相当比例的嵌入作用的发生。
