Formation of DNA nanoparticles in the presence of novel polyamine analogues: a laser light scattering and atomic force microscopic study
Formation of DNA nanoparticles in the presence of novel polyamine analogues: a laser light scattering and atomic force microscopic study
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DOI：
10.1093/nar/gkg936
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发表时间：
2004-01-01
影响因子：
14.9
通讯作者：
Thomas, TJ
中科院分区：
文献类型：
--
作者：
Vijayanathan, V;Thomas, T;Thomas, TJ
我们合成了天然多胺精胺（3- 4 - 3）的一个五胺（3 - 3-3-3）和两个六胺（3-3- 3-3-3和3-4-3-4 - 3）类似物，并利用光散射和原子力显微镜（AFM）技术研究了它们对pGL 3质粒DNA的凝聚作用。在10 mM二甲胂酸钠缓冲液中，3-4-3、去甲精胺（3-3-3）、3-3-3、3 - 3 - 3 - 3-3和3-4-3-4-3对pGL 3缩合的多胺中点浓度（EC 50）分别为11.3、10.6、1.5、0.49和0.52 μ M。动态激光光散射研究表明，随着多胺上正电荷数量的增加，质粒DNA颗粒的流体动力学半径减小。AFM数据显示，对于不同的聚胺，存在外径为117-191 nm的环形，平均高度为2.61 +/- 0.77 nm。AFM结果还揭示了中间结构的存在，包括那些显示DNA环形缠绕的环形结构。依赖于Na+浓度的EC_（50）表明精胺及其高价类似物与DNA的结合模式不同。我们的研究结果表明，与精胺相比，hexamines对DNA缩合的功效增加了20倍，并为DNA纳米颗粒形成的机制提供了新的见解。这些研究可能有助于开发新的非病毒基因载体。
We synthesized a pentamine (3-3-3-3) and two hexamine (3-3-3-3-3 and 3-4-3-4-3) analogues of the natural polyamine, spermine (3-4-3) and studied their effectiveness in condensing pGL3 plasmid DNA, using light scattering and atomic force microscopic (AFM) techniques. The midpoint concentration of the polyamines on pGL3 condensation (EC50) was 11.3, 10.6, 1.5, 0.49 and 0.52 muM, respectively, for 3-4-3, norspermine (3-3-3), 3-3-3-3, 3-3-3-3-3 and 3-4-3-4-3 in 10 mM Na cacodylate buffer. Dynamic laser light scattering study showed a decrease in hydrodynamic radii of plasmid DNA particles as the number of positive charges on the polyamines increased. AFM data showed the presence of toroids with outer diameter of 117-191 nm for different polyamines, and a mean height of 2.61 +/- 0.77 nm. AFM results also revealed the presence of intermediate structures, including those showing circumferential winding of DNA to toroids. The dependence of the EC50 on Na+ concentration suggests different modes of binding of spermine and its higher valent analogues with DNA. Our results show a 20-fold increase in the efficacy of hexamines for DNA condensation compared to spermine, and provide new insights into the mechanism(s) of DNA nanoparticle formation. These studies might help to develop novel nonviral gene delivery vehicles.