Skuridin S G, Salyanov V I, Damaschun G, Damaschun H, Misselwitz R, Kleinwächter V
Institute of Molecular Biology, Academy of Sciences of the U.S.S.R., Moscow.
Biophys Chem. 1990 Apr;35(2-3):143-53. doi: 10.1016/0301-4622(90)80004-q.
We have investigated the X-ray and optical properties (CD spectra and polarization microscopy) of liquid-crystalline phases and dispersions formed on pretreatment of low molecular weight DNA with the platinum(II) coordination complexes, cis-diammine-dichloroplatinum(II) (DDP), 2,2'-bipyridinedichloroplatinum(II) (1) and 2,2'-bipyridineethylenediammineplatinum(II) (2). It is demonstrated that the platination of DNA leads to the ordering of neighbouring molecules of DNA in liquid-crystalline phases being diminished. The intense bands observed in the CD spectra of liquid-crystalline dispersions prepared from DNA pretreated with 1 or 2 can be used to determine the orientation of the latter compounds with respect to the helical axis of the DNA and to detect distortions in the secondary structure of DNA. The possible causes of the appearance of the intense bands in the CD spectra of liquid-crystalline phases and alterations in the manner of packing of the molecules of DNA within them are discussed.
我们研究了用铂（II）配位络合物顺二氯二氨铂（II）（DDP）、2,2'-联吡啶二氯铂（II）（1）和2,2'-联吡啶乙二胺铂（II）（2）对低分子量DNA进行预处理后形成的液晶相和分散体的X射线和光学性质（圆二色光谱和偏振显微镜）。结果表明，DNA的铂化导致液晶相中相邻DNA分子的有序性降低。由用1或2预处理的DNA制备的液晶分散体的圆二色光谱中观察到的强吸收带可用于确定后一种化合物相对于DNA螺旋轴的取向，并检测DNA二级结构中的畸变。讨论了液晶相圆二色光谱中出现强吸收带的可能原因以及其中DNA分子堆积方式的改变。
