Marquet R, Colson P, Houssier C
Laboratoire de Chimie Macromoléculaire et Chimie Physique Université de Liège, Belgium.
J Biomol Struct Dyn. 1986 Oct;4(2):205-18. doi: 10.1080/07391102.1986.10506340.
At low ionic strength, spermine induces aggregation of native and H1-depleted chromatin at spermine/phosphate (Sp/P) ratios of 0.15 and 0.3, respectively. Physico-chemical methods (electric dichroism, circular dichroism and thermal denaturation) show that spermine, at Sp/P less than 0.15, does not appreciably alter the conformation of native chromatin and interacts unspecifically with all parts of chromatin DNA (linker as well as regions slightly or tightly bound to histones). In chromatin, the role of spermine could be more important in the stabilization of higher-order structure than in the condensation of the 30 nm solenoid. The addition of spermine to H1-depleted chromatin revealed two important features: (i) spermine can partially mimic the role of histone H1 in the condensation of chromatin; (ii) the core histone octamer does not appear to play any role in the aggregation process by spermine as DNA and H1-depleted chromatin aggregate at the same Sp/P ratio.
在低离子强度下，精胺分别在精胺/磷酸盐（Sp/P）比值为0.15和0.3时诱导天然染色质和H1缺失染色质的聚集。物理化学方法（电二色性、圆二色性和热变性）表明，当Sp/P小于0.15时，精胺不会明显改变天然染色质的构象，而是与染色质DNA的所有部分（连接区以及与组蛋白轻微或紧密结合的区域）非特异性相互作用。在染色质中，精胺在稳定高阶结构方面的作用可能比在30 nm螺线管的凝聚方面更重要。向H1缺失染色质中添加精胺揭示了两个重要特征：（i）精胺可以部分模拟组蛋白H1在染色质凝聚中的作用；（ii）核心组蛋白八聚体在精胺诱导的聚集过程中似乎不起任何作用，因为DNA和H1缺失染色质在相同的Sp/P比值下聚集。
