日本东京大学和科学技术振兴机构2月23日宣布，两家机构的研究人员借助纳米技术合成了只有1对碱基对的世界最短的双链RNA片段和只有3对碱基对组成的双链DNA片段。
两家机构23日联合发布新闻公报说，在碱基对形成DNA和RNA的过程中，如果碱基对少于4对的时候，它们就无法抵御周围水分子的影响，不能形成稳定的结构。但是，水分子难以突破生命体中的酶所具有的纳米尺寸的构造，因此在酶的帮助下，碱基对就如同躲在“安全的口袋”里，3对或者更少的碱基对也能形成双链DNA等，进行遗传信息的复制和表达。
研究人员受此启发，用有机化合物合成了一种纳米尺寸的“笼状构造物”，这种构造物创造出一个高0.6纳米、底面直径约2纳米的笼状空间。通过向该构造物中添加1－3对碱基对，研究人员成功合成了稳定的只有1对碱基对的双链RNA片段和只有3对碱基对组成的双链DNA片段。
新闻公报说，以这次研究成果为基础，今后有望从生命体内存在的各种长度和种类的DNA和RNA化合物中，按特定目的切取拥有相应性质和功能的部位，利用纳米空间，进行简便且低成本的基因诊断、化学分析和高效反应等。
此项成果于22日发表在英国《自然—化学》（Nature Chemistry）杂志创刊号的网络版上。（生物谷Bioon.com）
生物谷推荐原始出处：
Nature Chemistry Published online: 22 February 2009 | doi:10.1038/nchem.100
Minimal nucleotide duplex formation in water through enclathration in self-assembled hosts
Tomohisa Sawada1, Michito Yoshizawa1,3, Sota Sato1 & Makoto Fujita1,2
Short nucleotide fragments such as mono- and dinucleotides are generally unable to form stable hydrogen-bonded base pairs or duplexes in water. Within the hydrophobic pockets of enzymes, however, even short fragments form stable duplexes to transmit genetic information. Here, we demonstrate the efficient formation of hydrogen-bonded base pairs from mononucleotides in water through enclathration in the hydrophobic cavities of self-assembled cages. Crystallographic studies and 1H- and 15N-NMR spectroscopy clearly reveals pair-selective recognition of mononucleotides and the selective formation of an anti-Hoogsteen-type base pair in the cage's cavity. Within an analogous expanded cage, dinucleotides are also found to form a stable duplex in water. These results emphasize how hydrogen-bonded base pairing is amplified in a local hydrophobic area isolated from aqueous solution.
1 Department of Applied Chemistry, School of Engineering, The University of Tokyo, Japan
2 Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
4 Present address: Chemical Research Laboratory, Tokyo Institute of Technology, 4259, Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
