溶液中d(AT)_6的构象转化

d(AT)_6 Conformation Transition in Solutions

本文报道了溶液中d(AT)_6构象研究的结果。探讨了d(AT)_6的物化特征。d(AT)_6在0.05mol/L NaCl和4.5 mol/L NaCl中的UV和CD谱是典型的Z-和B-型DNA谱,UV熔化曲线形状依赖于盐的浓度。当盐浓度低于0.05 mol/L NaCl时,曲线有负斜率;而盐浓度大于0.05mol/L NaCl时,曲线的斜率变为正,即随盐浓度增加,T_m值增加。在链浓度的依赖性基础上,计算了两种构象的△H和△S。

In this paper the studied results of d(AT)6 conformation in solutions and physico-chemical characteristics were reported. The UV and CD spectra of d(AT)6 are typical of Z- and B-helices at 0.05mol/L and 4.5mol/L NaCl respectively. The shapes of the UV melting curves were found to depend on the concentration of the added salt. The curve had a negative slope at lower than 0.05mol/L NaCl and a positive slope above 0.05mol/L NaCl. Tm increased with increase of salt concentration. Based on the strand concentration dependence, the AH and AS of two conformations were calculated respectively.