Parodi S, Kendall F, Nicolini C
Nucleic Acids Res. 1975 Apr;2(4):477-86. doi: 10.1093/nar/2.4.477.
Ethidium bromide intercalation strongly effects the circular dichroism spectrum of DNA in the region of 230-300 mu, in a complex manner. In this report we present a study that quantitizes the relationships of the circular dichroism spectrum in the region of 230-300 mu and the ethidium bromide induced optical activity centered around 308 mu. We present evidence of two hidden cooperative bands that are probably the negative counterparts of the 308 mu band and 330 mu shoulder positive cooperative bands. The hidden band is quantitatively characterized. We confirm that the direct effect of ethidium bromide on the DNA spectrum is simply linearly proportional to the amount of intercalated dye. We also observe that the ethidium bromide enters freely when there is a molecule intercalated for every 3 sites, but that the intercalation is more difficult when the molecule intercalates at every second site.
溴化乙锭嵌入对230 - 300微米区域的DNA圆二色光谱有强烈影响,且方式复杂。在本报告中,我们进行了一项研究,量化了230 - 300微米区域的圆二色光谱与以308微米为中心的溴化乙锭诱导的光学活性之间的关系。我们提供了两个隐藏的协同带的证据,它们可能是308微米带和330微米肩峰正协同带的负对应物。对隐藏带进行了定量表征。我们证实,溴化乙锭对DNA光谱的直接影响与嵌入染料的量简单地呈线性比例关系。我们还观察到,当每3个位点有一个分子嵌入时,溴化乙锭可自由进入,但当分子每隔一个位点嵌入时,嵌入则更困难。