DNA Adsorption to Laterally Structured Charged Lipid Membranes

详细信息    查看全文

• 作者：Hauke Clausen-Schaumann and Hermann E. Gaub
• 刊名：Langmuir
• 出版年：1999
• 出版时间：November 9, 1999
• 年：1999
• 卷：15
• 期：23
• 页码：8246 - 8251
• 全文大小：403K
• 年卷期：v.15,no.23(November 9, 1999)
• ISSN：1520-5827

文摘

A macroscopic surface property, such as a surface's affinity for a certain polymer, may depend significantlyon surface parameters on the nanoscopic length scale, such as the size of areas with positive and negativesurface charge. In this study, polyelectrolyte adsorption to laterally structured charged surfaces wasinvestigated as a function of the size of the charged surface areas. Polydeoxyribonucleic acid (DNA) wasadsorbed onto supported cationic lipid bilayers which were imbedded in a matrix of negative surfacepotential, and the size of the cationic surface areas was varied from the micrometer down to the sub-nanometer length scale. The supported lipid bilayers and the adsorbed DNA were imaged with an atomicforce microscope, and the DNA adsorption was found to depend on the surface charge density and on thesize of the cationic lipid bilayers areas. While on purely cationic lipid bilayers larger than 20 nm a denselypacked layer of DNA could be observed, as expected, no DNA could be detected on molecular cocrystalsof cationic and anionic lipids where the diameter of the cationic lipid headgroups is only about 0.7 nm.On a 1:1 binary mixture of cationic and neutral lipids, on the other hand, the spacing between adjacentDNA strands was found to double, compared to the purely cationic lipid membranes.