Novel nucleic acids nanobiotechnology integrated with materials science

1.阳离子梳型共聚物与核酸的水溶性聚电解质复合物作为核酸结合蛋白的模型，我们研究了阳离子梳型共聚物--聚L-赖氨酸-接枝-葡聚糖(PLL-g-Dex)与阳离子梳型共聚物之间的可溶性聚电解质复合物。该共聚物形成了一种完全溶解的IPEC，其中DNA卷曲-球状结构的转变，即压实，被抑制了。该络合物的可溶性使我们能够通过光谱监测高碱性聚合物对DNA杂交的影响。我们发现，在生理相关条件下，相同数量的梳型共聚物提高了双链DNA和三链DNA的稳定性。此外，我们还发现这些共聚物促进了ds dna与其互补的单链dna和e…之间的链交换反应。结论1.更多的Xhibit核酸伴侣活性。阳离子梳型共聚物核酸杂交加速DNA杂交是体内基因表达、复制和重组的关键过程。然而，为了生物技术的目的，即使在低DNA浓度的情况下，提高杂交效率也是特别重要的。在生理相关离子条件下，聚赖氨酸-聚赖氨酸-纳米分子浓度的接枝-葡聚糖显着提高了DNA杂交效率200倍以上。阳离子梳型共聚物助推DNA纳米机器为了更好地应用和发展DNA纳米机器，其响应动力学、产量和序列选择性都有待提高。此外，DNA纳米机器目前在操作条件上有几个限制。在这项研究中，我们发现，通过杂交稳定和DNA链交换加速，聚L-赖氨酸-接枝-葡聚糖在温和的条件下，包括生理相关的条件下，甚至在非常低的链浓度(每升范围内的纳米分子数)下也能产生DNA纳米机器的强健和快速的响应。较少

1. Water soluble polyelectrolyte complex between cationic comb-type copolymer and nucleic acid We have been interested in the soluble interpolyelectrolyte complexes(IPEC)between DNA and the cationic comb-type copolymers, poly(L-lysine)-graft-dextran(PLL-g-Dex), consisting of a polylysine backbone and abundant hydrophilic graft chains of dextran as a model of nucleic acid-binding proteins. The copolymer forms a totally soluble IPEC in which the DNA coil-globule structural transition, i.e. compaction, is suppressed. The soluble nature of the complex enables us to spectroscopically monitor the effect of highly basic polymers on DNA hybridization. We found that an electrostatically equivalent amount of the comb-type copolymers increased stability of a double-stranded (ds)DNA and a triple-stranded DNA under physiological relevant conditions. Furthermore, we found that the copolymers stimulated the strand-exchange reaction between a ds DNA and its complementary single-stranded (ss)DNA, and e … More xhibit nucleic acid chaperoning activity.2. Acceleration of DNA hybridization by cationic comb-type copolymer Nucleic acid hybridization is a pivotal process in gene expression, replication and recombination in vivo. For biotechnology purposes, however, an increase in hybridization rate even at low DNA concentration is particularly important. Poly(L-lysine)-graft-dextran at nanomolar concentration significantly accelerated DNA-hybridization rate over 200-fold under physiologically relevant ionic conditions.3. Cationic comb-type copolymers for boosting DNA-fueled nanomachines For the better applications and developments of DNA nanomachines, their responding kinetics, output, and sequence-selectivity need to be improved. Furthermore, the DNA nanomachines currently have several limitations in operating conditions. In this study, we showed that poly(L-lysine)-graft-dextran produces the robust and quick responses of DNA nanomachines under moderate conditions including physiologically relevant conditions even at very low strand concentrations(nanomoles per liter range)through hybrid stabilization and DNA strand exchange acceleration. Less