Pan Wei, Zhou Jihan, Yin Yudan, Wen Hao, Liang Dehai
Beijing National Laboratory for Molecular Sciences and the Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, P. R. China.
Soft Matter. 2015 Jun 21;11(23):4705-9. doi: 10.1039/c5sm00552c.
How polyamines such as spermidine cooperate with histone to condense and de-condense DNA during transcription has not been clarified. In this work, using the complex of DNA and poly(L-lysine) (PLL) at +/- ratio of 0.5 as a model of nucleosome, we monitored the de-condensation of DNA in the presence of spermidine. As revealed by the results from atomic force microscopy and time-resolved laser light scattering, spermidine was able to transform the spherical complex into a core-shelled structure, with the hard core being the DNA-PLL complex and the soft shell being DNA and spermidine. The soft shell evolved into a coiled DNA conformation with time. Such a local de-condensation process should be helpful in understanding the DNA transcription and cell division process in vivo.
多胺如亚精胺在转录过程中如何与组蛋白协同作用使DNA浓缩和解浓缩尚不清楚。在这项工作中，我们以DNA与聚（L-赖氨酸）（PLL）比例为0.5的复合物作为核小体模型，监测了亚精胺存在下DNA的解浓缩情况。原子力显微镜和时间分辨激光光散射结果表明，亚精胺能够将球形复合物转变为核壳结构，硬核为DNA-PLL复合物，软壳为DNA和亚精胺。软壳随时间演变成盘绕的DNA构象。这种局部解浓缩过程应有助于理解体内的DNA转录和细胞分裂过程。
