Huang H C, Cole R D
J Biol Chem. 1984 Nov 25;259(22):14237-42.
Salt induces aggregation of large chromatin fragments maximally at 150-200 mM NaCl. The soluble fragments are depleted of H1 histones while the aggregated fragments are enriched. H1 histones did not equilibrate between the soluble and insoluble chromatin fractions when they were recycled through the process of salt-induced aggregation. The chromatin fragments that resisted aggregation retained more H1c subtype than they did H1 ab, correlating with previous results which showed complexes of H1c with DNA resisted salt-induced aggregation much more than complexes of DNA with other subtypes. The chromatin that was soluble at physiological concentrations of NaCl was DNase I sensitive and enriched in acetylated core histones. We conclude that H1 histone is nonuniformly distributed in chromatin in a stable pattern that probably correlates with the different degrees of condensation known to exist in vivo.
盐在150 - 200 mM NaCl浓度时能最大程度地诱导大染色质片段聚集。可溶性片段中H1组蛋白减少，而聚集片段中H1组蛋白富集。当H1组蛋白通过盐诱导聚集过程循环时，它们在可溶性和不溶性染色质组分之间不会达到平衡。抵抗聚集的染色质片段保留的H1c亚型比H1 ab亚型更多，这与之前的结果相关，即H1c与DNA的复合物比其他亚型与DNA的复合物更能抵抗盐诱导的聚集。在生理浓度NaCl下可溶的染色质对DNase I敏感，且富含乙酰化核心组蛋白。我们得出结论，H1组蛋白以稳定模式在染色质中呈非均匀分布，这可能与体内已知存在的不同程度的凝聚相关。
