Pfeiffer Indriati, Höök Fredrik
Department of Applied Physics, Chalmers University of Technology and Göteborg University, 41296 Göteborg, Sweden.
J Am Chem Soc. 2004 Aug 25;126(33):10224-5. doi: 10.1021/ja048514b.
By mimicking Nature's way of utilizing multivalent interactions, we introduce in the present work a novel method to improve the strength of cholesterol-based DNA coupling to lipid membranes. The bivalent coupling of DNA was accomplished by hybridization between a 15-mer DNA and a 30-mer DNA, being modified with cholesterol in the 3' and 5' end, respectively. Compared with DNA modified with one cholesterol moiety only, the binding strength to lipid membranes appears to be significantly stronger and even irreversible over the time scale investigated ( approximately 1 hr). First, this means that the bivalent coupling can be used to precisely control the number of DNA per lipid-membrane area. Second, the strong coupling is demonstrated to facilitate DNA-hybridization kinetics studies. Third, exchange of DNA between differently DNA-modified vesicles was demonstrated to be significantly reduced. The latter condition was verified via site-selective and sequence-specific sorting of differently DNA-modified lipid vesicles on a low-density cDNA array. This means of spatially control the location of different types of lipid vesicles is likely to find important applications in relation to the rapid progress currently made in the protein chip technology and the emerging need for efficient ways to develop membrane protein arrays.
通过模仿自然界利用多价相互作用的方式，我们在本工作中引入了一种新方法，以提高基于胆固醇的DNA与脂质膜耦合的强度。DNA的二价耦合通过15聚体DNA与30聚体DNA之间的杂交实现，它们分别在3'端和5'端用胆固醇修饰。与仅用一个胆固醇部分修饰的DNA相比，在所研究的时间尺度（约1小时）内，其与脂质膜的结合强度明显更强，甚至是不可逆的。首先，这意味着二价耦合可用于精确控制每个脂质膜区域的DNA数量。其次，强耦合被证明有助于DNA杂交动力学研究。第三，不同DNA修饰的囊泡之间的DNA交换被证明显著减少。通过在低密度cDNA阵列上对不同DNA修饰的脂质囊泡进行位点选择性和序列特异性分选，验证了后一种情况。这种在空间上控制不同类型脂质囊泡位置的方法，可能会在蛋白质芯片技术目前的快速发展以及开发膜蛋白阵列的高效方法的新需求方面找到重要应用。
