Libertini L J, Small E W
Nucleic Acids Res. 1987 Aug 25;15(16):6655-64. doi: 10.1093/nar/15.16.6655.
The low-salt transition of chromatin core particles is reversible if the monovalent cation concentration is kept above 0.2 mM. Exposure of the particles to salt concentrations below this value results in a nonreversible secondary transition. The nonreversible changes are relatively slow with a half-time of about 15 minutes. Once exposed to such low ionic strength, the particles then begin to refold with increasing salt in at least two steps over a much higher ionic strength range than is required for the usual low-salt transition. The refolding is very fast, with a half-time less than a minute. Small differences between particles which had or had not been exposed to very low salt persist even when the particles are returned to near physiological ionic strengths.
如果单价阳离子浓度保持在0.2 mM以上，染色质核心颗粒的低盐转变是可逆的。将颗粒暴露于低于该值的盐浓度会导致不可逆的二级转变。不可逆变化相对较慢，半衰期约为15分钟。一旦暴露于如此低的离子强度，颗粒随后开始在比通常低盐转变所需的离子强度范围高得多的范围内，至少分两步随着盐浓度增加而重新折叠。重新折叠非常快，半衰期不到一分钟。即使颗粒恢复到接近生理离子强度，暴露于极低盐浓度和未暴露于极低盐浓度的颗粒之间的微小差异仍然存在。
