Baxevanis A D, Godfrey J E, Moudrianakis E N, Park K, Fasman G D
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
Biochemistry. 1990 Jan 30;29(4):973-6. doi: 10.1021/bi00456a019.
The circular dichroism (CD) of freshly prepared chicken erythrocyte core histones has been reexamined in high concentrations of ammonium sulfate and sodium chloride, conditions which cause drastic changes in the solubility and aggregative properties of these proteins. After sample clarification by ultracentrifugation, no significant net changes are detected in the secondary structure of the core histones in the range of 2.0-2.5 M ammonium sulfate. There is also no significant difference between the CD spectra of histone solutions in 2 M sodium chloride and clarified solutions of histones in high concentrations of ammonium sulfate. It was observed that sample clarification by ultracentrifugation immediately prior to taking CD spectra was necessary for signal stabilization, especially under conditions which begin to favor crystallization of the histones.
在高浓度硫酸铵和氯化钠条件下，对新制备的鸡红细胞核心组蛋白的圆二色性（CD）进行了重新研究，这些条件会导致这些蛋白质的溶解度和聚集特性发生剧烈变化。通过超速离心使样品澄清后，在2.0 - 2.5 M硫酸铵范围内，未检测到核心组蛋白二级结构有明显的净变化。2 M氯化钠中的组蛋白溶液的CD光谱与高浓度硫酸铵中澄清的组蛋白溶液的CD光谱之间也没有显著差异。观察到在采集CD光谱之前立即通过超速离心使样品澄清对于信号稳定是必要的，特别是在开始有利于组蛋白结晶的条件下。
