Takashima K, Kawashima S, Imahori K
J Biochem. 1984 Oct;96(4):1071-8. doi: 10.1093/oxfordjournals.jbchem.a134924.
Polynucleosomes with a definite length (about 4,500 base pairs) were prepared from chicken erythrocyte nuclei without depleting magnesium ions from the medium. The polynucleosomes in the presence of Mg2+ ions as well as monovalent salts were more compact than those with monovalent salts alone. We minimized the occurrence of nicks in the DNA of nucleosome fiber during the preparation. When histones H1 and H5 were completely removed from polynucleosomes, linker histone-depleted polynucleosomes sedimented slower than the original ones. When isolated histone H1 or H5 was reassembled with linker histone-depleted polynucleosomes, no significant difference was observed among the reconstituted polynucleosomes with histone H1, the reconstituted polynucleosomes with histone H5, and the original polynucleosomes. We concluded that histones H1 and H5 are similar in their effects on higher order structure of polynucleosomes, as far as can be judged from such characteristics as sedimentation velocity, linker histone content, and the patterns of nuclease digestion.
从鸡红细胞核中制备出具有确定长度（约4500个碱基对）的多核小体，且培养基中不除去镁离子。存在镁离子以及单价盐时的多核小体比仅存在单价盐时的多核小体更加紧密。在制备过程中，我们尽量减少核小体纤维DNA中切口的出现。当从多核小体中完全去除组蛋白H1和H5时，缺乏连接组蛋白的多核小体沉降速度比原始多核小体慢。当将分离的组蛋白H1或H5与缺乏连接组蛋白的多核小体重组时，重组有组蛋白H1的多核小体、重组有组蛋白H5的多核小体与原始多核小体之间未观察到显著差异。我们得出结论，就沉降速度、连接组蛋白含量和核酸酶消化模式等特征而言，组蛋白H1和H5对多核小体高级结构的影响相似。
