Monitoring the binding of metal cations and histones to DNA in real time using fluorescence assays  

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 Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China

出　　处：《Chinese Science Bulletin》2011年第11期1080-1085,共6页

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

摘　　要：The binding of cations (Na +,K +,Mg 2+,Ca 2+,Mn 2+) and histones to DNA can be studied using fluorescence assays.Here,we measured the fluorescence intensity and fluorescence anisotropy of DNA and DNA-histone complexes in the presence of cations.We demonstrate that when different cations are added into a DNA solution,the fluorescence intensities of the stained DNA are reduced by different amounts.Compared with divalent cations,monovalent cations had a weaker effect on fluorescence intensity and fluorescence anisotropy.Divalent (Mn 2+,Mg 2+,Ca 2+) cations markedly enhanced the fluorescence anisotropy of DNA.The binding modes of monovalent and divalent cations to DNA may be different.Divalent cations can change the structure of DNA molecules,or promote the assembly of DNA strands.The addition of histones causes DNA condensation,which mostly occurs during the first few seconds.Cation binding to DNA is abrupt,and is much faster than that of histones.The binding of cations （Na＋, K＋, Mg2＋, Ca2＋, Mn2＋） and histones to DNA can be studied using fluorescence assays. Here, we measured the fluorescence intensity and fluorescence anisotropy of DNA and DNA-histone complexes in the presence of cations. We demonstrate that when different cations are added into a DNA solution, the fluorescence intensities of the stained DNA are reduced by different amounts. Compared with divalent cations, monovalent cations had a weaker effect on fluorescence intensity and fluorescence anisotropy. Divalent （Mn2＋, Mg2＋, Ca2＋） cations markedly enhanced the fluorescence anisotropy of DNA. The binding modes of monovalent and divalent cations to DNA may be different. Divalent cations can change the structure of DNA molecules, or promote the assembly of DNA strands. The addition of histones causes DNA condensation, which mostly occurs during the first few seconds. Cation binding to DNA is abrupt, and is much faster than that of histones.

关 键 词：DNA结合 金属阳离子 荧光检测 组蛋白 实时检测 荧光各向异性 二价阳离子 监测 

分 类 号：Q523[生物学—生物化学]