Koch M H, Vega M C, Sayers Z, Michon A M
Eur Biophys J. 1987;14(5):307-19. doi: 10.1007/BF00254896.
Solutions of rat liver and chicken erythrocyte chromatin at different ionic strengths were characterized by synchrotron X-ray solution scattering, ultracentrifugation, density and viscosity measurements. Previous observations on nuclei were extended to rat liver, calf thymus and yeast nuclei. It is shown that with monovalent cations condensation is independent of the nature of the cation whereas with divalent cations there are significant differences related to the preference of base binding over phosphate binding. The consistency of hydrodynamic and scattering results confirm the view that chromatin in solution at low ionic strength has a helix-like superstructure. A survey of X-ray and neutron scattering results in the literature shows that previous interpretations, e.g. in terms of a 10 nm filament, are incompatible with the experimental data at low resolution.
通过同步加速器X射线溶液散射、超速离心、密度和粘度测量对不同离子强度下大鼠肝脏和鸡红细胞染色质溶液进行了表征。先前对细胞核的观察扩展到了大鼠肝脏、小牛胸腺和酵母细胞核。结果表明，对于单价阳离子，凝聚作用与阳离子的性质无关，而对于二价阳离子，由于碱基结合优先于磷酸结合，存在显著差异。流体动力学和散射结果的一致性证实了这样一种观点，即低离子强度溶液中的染色质具有螺旋状超结构。对文献中X射线和中子散射结果的调查表明，先前的解释，例如关于10纳米细丝的解释，与低分辨率下的实验数据不相符。
