Lipophilic Oligonucleotides Spontaneously Insert into Lipid Membranes, Bind Complementary DNA Strands, and Sequester into Lipid-Disordered Domains
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- 作者：Andreas Bunge ; Anke Kurz ; Anne-Kathrin Windeck ; Thomas Korte ; Wolfgang Flasche ; Jü ; rgen Liebscher ; Andreas Herrmann ; Daniel Huster
- 刊名：Langmuir
- 出版年：2007
- 出版时间：April 10, 2007
- 年：2007
- 卷：23
- 期：8
- 页码：4455 - 4464
- 全文大小：179K
- 年卷期：v.23,no.8(April 10, 2007)
- ISSN：1520-5827
文摘
For the development of surface functionalized bilayers, we have synthesized lipophilic oligonucleotides to combinethe molecular recognition mechanism of nucleic acids and the self-assembly characteristics of lipids in planar membranes.A lipophilic oligonucleotide consisting of 21 thymidine units and two lipophilic nucleotides with an 
-tocopherolmoiety as a lipophilic anchor was synthesized using solid-phase methods with a phosphoramadite strategy. Theinteraction of the water soluble lipophilic oligonucleotide with vesicular lipid membranes and its capability to bindcomplementary DNA strands was studied using complementary methods such as NMR, EPR, DSC, fluorescencespectroscopy, and fluorescence microscopy. This oligonucleotide inserted stably into preformed membranes from theaqueous phase. Thereby, no significant perturbation of the lipid bilayer and its stability was observed. However, thenon-lipidated end of the oligonucleotide is exposed to the aqueous environment, is relatively mobile, and is free tointeract with complementary DNA strands. Binding of the complementary single-stranded DNA molecules is fast andaccomplished by the formation of Watson-Crick base pairs, which was confirmed by 1H NMR chemical shift analysisand fluorescence resonance energy transfer. The molecular structure of the membrane bound DNA double helix isvery similar to the free double-stranded DNA. Further, the membrane bound DNA double strands also undergo regularmelting. Finally, in raft-like membrane mixtures, the lipophilic oligonucleotide was shown to preferentially sequesterinto liquid-disordered membrane domains.
-tocopherolmoiety as a lipophilic anchor was synthesized using solid-phase methods with a phosphoramadite strategy. Theinteraction of the water soluble lipophilic oligonucleotide with vesicular lipid membranes and its capability to bindcomplementary DNA strands was studied using complementary methods such as NMR, EPR, DSC, fluorescencespectroscopy, and fluorescence microscopy. This oligonucleotide inserted stably into preformed membranes from theaqueous phase. Thereby, no significant perturbation of the lipid bilayer and its stability was observed. However, thenon-lipidated end of the oligonucleotide is exposed to the aqueous environment, is relatively mobile, and is free tointeract with complementary DNA strands. Binding of the complementary single-stranded DNA molecules is fast andaccomplished by the formation of Watson-Crick base pairs, which was confirmed by 1H NMR chemical shift analysisand fluorescence resonance energy transfer. The molecular structure of the membrane bound DNA double helix isvery similar to the free double-stranded DNA. Further, the membrane bound DNA double strands also undergo regularmelting. Finally, in raft-like membrane mixtures, the lipophilic oligonucleotide was shown to preferentially sequesterinto liquid-disordered membrane domains.