Modulation of density and orientation of amphiphilic DNA anchored to phospholipid membranes. I. Supported lipid bilayers.

Journal article

In the present series of papers, we describe the results of a systematic study on the anchoring of cholesterol-tagged oligonucleotides to phospholipids bilayers followed by membrane-assisted hybridization of the complementary strand in solution. This paper describes the anchoring of novel cholesterol-modified DNA-18mers in supported lipid bilayers (SLB) of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine: we compared the behavior of two anchoring functionalities differing in the number of cholesterol units and in the length of a spacer group. Quartz Crystal Microbalance with impedance monitoring (QCM-Z) measurements showed that both oligonucleotides insert into the bilayer membrane through cholesterol anchoring; however, dramatic differences, in terms of surface organization and thickness, are found as the number of anchoring units increases. In the case of multiple cholesterol units, a peculiar three-regimes concentration dependence was revealed and correlated to the effective size of the adsorbing units. Interestingly, for high oligonucleotide concentration, the adsorption process was rationalized in terms of a compaction model of amphiphilic DNA molecules. QCM-Z temperature cycles of the SLB-anchored double strands provided clear evidence for reversible hybridization at the bilayer interface.

Authors: Gambinossi, F; Banchelli, M; Durand, A; Berti, D; Brown, T

• Publication status: Published
• Journal: journal of physical chemistry. B
• Volume: 114
• Issue: 21
• Pages: 7338-7347
• Publication date: 2010-06-01
• DOI: 10.1021/jp100730x
• EISSN: 1520-5207
• ISSN: 1520-6106
• Language: English
• Keywords: DNA; Quartz; Lipid Bilayers; Cholesterol; Oligonucleotides; Phosphatidylcholines