AFFINITY CHROMATOGRAPHIC PURIFICATION OF NUCLEOSOMES CONTAINING TRANSCRIPTIONALLY ACTIVE DNA-SEQUENCES
AFFINITY CHROMATOGRAPHIC PURIFICATION OF NUCLEOSOMES CONTAINING TRANSCRIPTIONALLY ACTIVE DNA-SEQUENCES
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DOI：
10.1016/0022-2836(87)90698-x
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发表时间：
1987-07-20
影响因子：
5.6
通讯作者：
ALLFREY, VG
中科院分区：
文献类型：
--
作者：
ALLEGRA, P;STERNER, R;ALLFREY, VG
转录活性染色质中核小体核心的解折叠揭示了组蛋白H3的巯基，使其可被SH试剂接近。这表明活性基因的核小体可以选择性地保留在有机汞/琼脂糖柱上。当大鼠肝细胞核通过微球菌核酸酶有限消化释放的核小体通过Hg亲和柱时，从保留的核小体部分中分离出紧凑的珠状核小体的径流部分。虽然两者都含有单体长度的DNA和完整的核心组蛋白，组蛋白在保留的馏分是超乙酰化。斑点杂交显示，汞结合的核小体部分被富集在肝细胞（血清白蛋白和转铁蛋白基因）转录的DNA序列，而脑特异性基因（前脑啡肽原）没有保留，但出现在核小体的径流部分。结果进行了讨论，根据其他证据连接超乙酰化组蛋白H3和H4的构象变化在中间的核小体核心。
The unfolding of nucleosome cores in transcriptionally active chromatin uncovers the sulfhydryl groups of histone H3, making them accessible to SH-reagents. This has suggested that nucleosomes from active genes could be retained selectively on organomercurial/agarose columns. When nucleosomes released from rat liver nuclei by limited digestion with micrococcal nuclease were passed through an Hg affinity column, a run-off fraction of compact, beaded nucleosomes was separated from a retained nucleosome fraction. Although both contained monomer-length DNA and a full complement of core histones, histones in the retained fraction were hyperacetylated. Dot blot hybridizations showed the Hg-bound nucleosome fraction to be enriched in DNA sequences transcribed by hepatocytes (serum albumin and transferrin genes), while a brain-specific gene (preproenkephalin) was not retained, but appeared in the nucleosomes of the run-off fraction. The results are discussed in light of other evidence linking hyperacetylation of histones H3 and H4 to conformational changes at the middle of the nucleosome core.