Evdokimov Iu M, Salianov V I, Akimenko N M, Varshavskiĭ Ia M
Mol Biol (Mosk). 1977 Mar-Apr;11(2):303-9.
The experimental data indicating that the amplitude of the negative band in CD spectra of DNA compact particles forming in PEG-containing water-salt solutions intensifies with the decrease of DNA molecular weight are presented. This effect is not explained by the light scattering on the compact particles. The presence of the negative band in CD spectrum of DNA compact particles is interpreted as result of formation of dichrographic-active "microcrystalline" region ("domains") (if DNA compact particles are formed from double-stranded molecules with unaltered secondary structure); it is also supposed that the number of these regions in the particle and their dichrographic activity doesn't depend on the particles size. This interpretation is in agreement with experimental data on the increase of the number of compact particles with the decrease of DNA molecular weight. Proportionality coefficient in the linear dependence of the amplitude of negative band on the size of DNA compact particles in solution depends apparently on dichrographic activity of "microcrystalline" regions, and this activity is connected with structural peculiarities of initial DNA molecules.
本文给出了实验数据，这些数据表明，在含聚乙二醇的水盐溶液中形成的DNA紧密颗粒的圆二色光谱中，负带的振幅随DNA分子量的降低而增强。这种效应无法用紧密颗粒上的光散射来解释。DNA紧密颗粒圆二色光谱中负带的出现被解释为二色性活性“微晶”区域（“结构域”）形成的结果（如果DNA紧密颗粒由二级结构未改变的双链分子形成）；还推测颗粒中这些区域的数量及其二色性活性不取决于颗粒大小。这一解释与DNA分子量降低时紧密颗粒数量增加的实验数据一致。溶液中负带振幅与DNA紧密颗粒大小的线性依赖关系中的比例系数显然取决于“微晶”区域的二色性活性，而这种活性与初始DNA分子的结构特性有关。
