DNA与不溶性单分子层的表面络合。二价抗衡离子的影响。

Surface complexation of DNA with insoluble monolayers. Influence of divalent counterions.

作者信息

McLoughlin D, Dias R, Lindman B, Cardenas M, Nylander T, Dawson K, Miguel M, Langevin D

机构信息

Laboratoire de Physique des Solides, Université Paris Sud, 91405 Orsay, France.

出版信息

Langmuir. 2005 Mar 1;21(5):1900-7. doi: 10.1021/la047700s.

DOI:10.1021/la047700s

PMID:15723487

Abstract

DNA interacts with insoluble monolayers made of cationic amphiphiles as well as with monolayers of zwitterionic lipids in the presence of divalent ions. Binding to dioctadecyldimethylammonium bromide (DODAB) or distearoyl-sn-glycero-3-phosphocholine (DSPC) monolayers in the presence of calcium is accompanied by monolayer expansion. For the positively charged DODAB monolayer, this causes a decrease of surface potential, while an increase is observed for the DSPC monolayers. Binding to dipalmitoyl-sn-glycero-3-phosphocholine preserves most of the liquid expanded-liquid condensed coexistence region. The liquid condensed domains adopt an elongated morphology in the presence of DNA, especially in the presence of calcium. The interaction of DNA with phospholipid monolayers is ion specific: the presence of calcium leads to a stronger interaction than magnesium and barium. These results were confirmed by bulk complexation studies.

摘要

在二价离子存在的情况下，DNA与由阳离子两亲物制成的不溶性单分子层以及两性离子脂质的单分子层相互作用。在钙存在的情况下，与二辛基二甲基溴化铵（DODAB）或二硬脂酰-sn-甘油-3-磷酸胆碱（DSPC）单分子层结合会伴随单分子层膨胀。对于带正电荷的DODAB单分子层，这会导致表面电位降低，而对于DSPC单分子层则观察到表面电位升高。与二棕榈酰-sn-甘油-3-磷酸胆碱结合保留了大部分液体扩张-液体凝聚共存区域。在DNA存在下，尤其是在钙存在下，液体凝聚域呈现出细长的形态。DNA与磷脂单分子层的相互作用具有离子特异性：钙的存在导致的相互作用比镁和钡更强。这些结果通过本体络合研究得到了证实。