光谱法研究灿烂甲酚蓝与DNA的相互作用

利用紫外-可见(UV/Vis)光谱法研究了小分子染料灿烂甲酚蓝(BCB)与小牛胸腺DNA(ct DNA)的相互作用。实验表明，DNA在低浓度时，BCB能结合DNA形成1∶1的化合物，结合常数为4.3×104 L·mol-1，DNA与BCB的主要结合方式是“静电作用”方式;而在较高浓度时，则变成“嵌入作用”方式。为了进一步证明BCB分子嵌入到DNA, 利用了羟丙基-β环糊精(HP-β-CD)与BCB的包合行为来研究。实验证明，BCB分子能进入HP-β-CD的疏水性空腔形成包合物, 稳定常数为1.98×103 L·mol-1;高浓度DNA存在时，BCB分子从HP-β-CD空腔中离解而与DNA发生嵌入作用。据此可推断出BCB分子能嵌入到DNA的双螺旋沟槽中。BCB分子属经典的嵌入剂。

Spectroscopic Studies of Interaction of Brilliant Cresyl Blue and DNA

The interaction of dye brilliant cresyl blue (BCB), which features a phenoxonium group, with hydroxypropyl-beta-cyclodextrinl and DNA in aqueous solution was studied by spectroscopic methods. The experimental results indicate that BCB can be included into the hydrophobic cavity of HP-beta-CD to form an inclusion, a complex with a stability constant of 1.98 x 10(3) L x mol(-1). At low DNA concentrations, BCB can be bound to DNA to form a 1:1 association complex with the binding constant of 4.3 x 10(4) mol x L(-1), and the major binding model of BCB to DNA is "electrostatic binding". However, the major binding model changes to "intercalative binding" at high DNA concentrations. In addition, the interactions of BCB-(HP-beta-CD) inclusion complex and DNA have been investigated. The results suggest that BCB displayed a high affinity for DNA and the inclusion complex decomposed when it was bound to DNA.