pH对十二烷基二甲基氧化胺与DNA相互作用的影响

Effect of pH on the Interaction Between DNA and N,N-Dimethyldodecylamine N-oxide

通过相图研究了pH值对十二烷基二甲基氧化胺(DDAO)-鲑鱼精DNA复合物的影响。实验结果表明,非离子态DDAO与DNA只能发生弱的疏水作用,阳离子态DDAO在低浓度时不能诱导DNA发生构象转变。只有当DDAO浓度高于非离子态临界胶束浓度并且达到临界pH值时,DDAO才能与DNA发生强烈的静电相互作用而导致相分离。

The interaction between N,N-dimethyldodecylamine N-oxide（DDAO） and salmon sperm DNA was studied. The Effect of pH on DDAO-DNA complex was investigated via the phase diagram. The hydrophobic interaction between non-ionic species DDAO and DNA was quite weak. At low DDAO concentrations, the cationic species of DDAO （protonated form） could not induce the conformational transformation of DNA either. As the concentration of DDAO was higher than the critical micelle concentration of non-ionic species, electrostatic attraction induced DDAO to combine with DNA strongly and phase separation at critical pH value.