Study of the interaction of DNA and histones by spin-stretching and droplet evaporation  

作　　者：LIU YuYing WANG PengYe DOU ShuoXing ZHANG WeiWei WANG XueJin SANG HongYi 

机构地区：[1]College of Science, China Agricultural University, Beijing 100083, China [2]Key Laboratory of Soft Matter Physics and Beifing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China

出　　处：《Chinese Science Bulletin》2011年第12期1234-1240,共7页

基　　金：supported by the National Natural Science Foundation of China (60025516 and 10334100);the Scientific Research Start-up Foundation of China Agricultural University (2009-2-05)

摘　　要：Molecular combing is a powerful and simple method for aligning DNA molecules onto a surface. Using this technique combined with fluorescence microscopy, DNA-histone complexes are stretched on a hydrophobic polymethyl methacrylate (PMMA) surface and observed directly. We have developed a new method to stretch single DNA-histone complexes, termed spin-stretching. The results show that the histones markedly enhance DNA binding to the PMMA surface. DNA winds around the histones and therefore decreases in length. The number of histones that bind to each DNA molecule is found to correlate with the histone concentration. The combed DNA-histone complexes are found to depend on two factors: the binding force on the surface and the centrifugal force at its local position. Na+ ions should compete with histones for binding to DNA; however, the observed competitive binding effect of Na+ ions at low concentrations was negligible.Molecular combing is a powerful and simple method for aligning DNA molecules onto a surface. Using this technique combined with fluorescence microscopy, DNA-histone complexes are stretched on a hydrophobic polymethyl methacrylate （PMMA） sur- face and observed directly. We have developed a new method to stretch single DNA-histone complexes, termed spin-stretching. The results show that the histones markedly enhance DNA binding to the PMMA surface. DNA winds around the histones and therefore decreases in length. The number of histones that bind to each DNA molecule is found to correlate with the histone con- centration. The combed DNA-histone complexes are found to depend on two factors： the binding force on the surface and the centrifugal force at its local position. Na＋ ions should compete with histones for binding to DNA; however, the observed competi- tive binding effect of Na＋ ions at low concentrations was negligible.

关 键 词：DNA分子 组蛋白 相互作用 液滴蒸发 拉伸 聚甲基丙烯酸甲酯 蛋白复合物 DNA结合 

分 类 号：Q504[生物学—生物化学]