Institute of Medical Physics and Biophysics, University of Leipzig, Hartelstr. 16-18, D-04107 Leipzig, Germany.
J Phys Chem B. 2009 Dec 24;113(51):16425-34. doi: 10.1021/jp9067747.
Cholesterol-based lipophilic oligonucleotides incorporated into lipid membranes were studied using solid-state NMR, differential scanning calorimetry, and fluorescence methods. Lipophilic oligonucleotides can be used to build nanotechnological structures on membrane surfaces, taking advantage of the specific Watson-Crick base pairing. We used a cholesteryl-TEG anchor first described by Pfeiffer and Hook (J. Am. Chem. Soc. 2004, 126, 10224-10225). The cholesterol-based anchor molecules were found to incorporate well into lipid membranes without disturbing the bilayer structure and dynamics. In contrast to cholesterol, which is known to induce significant condensation of the membrane lipids, the cholesteryl-TEG anchor does not display this property. When the cholesteryl-TEG moiety was covalently bound to an oligonucleotide, the resulting lipophilic DNA molecules inserted spontaneously into lipid membranes without altering their structure. The duplex formed by two complementary cholesteryl-TEG oligonucleotides had increased thermodynamic stability compared to the same oligonucleotides without the anchor, both in solution and incorporated into lipid membranes. Since the cholesteryl-TEG anchor lacks the characteristic properties of cholesterol, oligonucleotides modified with this anchor are equally distributed between liquid-disordered and liquid-ordered domains in "raft" forming membranes. As an example of an application of these lipophilic oligonucleotides, cholesteryl-TEG-DNA was incorporated into supported lipid bilayers formed on polyelectrolyte-coated silica microparticles. The modified oligonucleotides were stably inserted into the lipid membrane and retained their recognition properties, therefore enabling further functionalization of the particles.
亲脂性胆固醇寡核苷酸整合到脂质膜中，利用固态 NMR、差示扫描量热法和荧光方法进行了研究。亲脂性寡核苷酸可用于利用特定的沃森-克里克碱基配对在膜表面构建纳米技术结构。我们使用了 Pfeiffer 和 Hook 首次描述的胆固醇-TEG 接头（J. Am. Chem. Soc. 2004, 126, 10224-10225）。发现胆固醇基锚定分子很好地整合到脂质膜中，而不会干扰双层结构和动力学。与已知会引起膜脂显著凝聚的胆固醇不同，胆固醇-TEG 锚定分子不具有这种性质。当胆固醇-TEG 部分与寡核苷酸共价结合时，所得的亲脂性 DNA 分子会自发插入脂质膜中，而不会改变其结构。与没有锚定的相同寡核苷酸相比，由两个互补的胆固醇-TEG 寡核苷酸形成的双链体在溶液中和整合到脂质膜中时具有更高的热力学稳定性。由于胆固醇-TEG 锚定缺乏胆固醇的特征性质，用这种锚定修饰的寡核苷酸在“筏”形成膜中的无序相和有序相之间均匀分布。作为这些亲脂性寡核苷酸应用的一个例子，胆固醇-TEG-DNA 被整合到聚电解质涂覆的二氧化硅微球上形成的支撑脂质双层中。修饰的寡核苷酸稳定地插入脂质膜中并保留其识别特性，因此能够进一步对颗粒进行功能化。
