Nordén B
Biophys Chem. 1978 Sep;8(4):385-91. doi: 10.1016/0301-4622(78)80020-9.
Linear dichroism (LD) gives useful information on the interaction between DNA and the directly acting carcinogen N-acetoxy-N-2acetylaminofluorene (AAAF). In 50% methanol solvent with low ionic strength only a weak complex (van der Waals) appears. However, above 40 degrees C strand separation takes place and a covalent aminofluorene complex forms. After renaturation a characteristic positive LD band is observed at 306 nm. The average angular orientation of the long-axis of the fluorene moiety (47 degrees to the local helix axis) is inconsistent with intercalation. It can be explained for instance by a free rotation around a C(DNA)-N(aminofluorene) bond or by a major groove site. The occupation density was 1--2 aminofluorene residues per 100 bases. With native DNA, AAAF slowly forms a covalent complex which has a negative LD at 307 nm. The orientation (70--90 degrees) is consistent with steric direction by the strand.
线性二色性（LD）为DNA与直接作用致癌物N-乙酰氧基-N-2-乙酰氨基芴（AAAF）之间的相互作用提供了有用信息。在低离子强度的50%甲醇溶剂中，仅出现弱复合物（范德华力）。然而，在40℃以上会发生链分离，并形成共价氨基芴复合物。复性后，在306nm处观察到特征性的正LD带。芴部分长轴的平均角取向（与局部螺旋轴成47度）与嵌入不一致。例如，这可以通过围绕C（DNA）-N（氨基芴）键的自由旋转或通过大沟位点来解释。占据密度为每100个碱基有1至2个氨基芴残基。对于天然DNA，AAAF缓慢形成共价复合物，该复合物在307nm处具有负LD。其取向（70-90度）与链的空间方向一致。
