通过使用通用超光开关调节拓扑结构来实现光开关核酸催化活性。
Photoswitch nucleic acid catalytic activity by regulating topological structure with a universal supraphotoswitch.
作者信息
Liang Xingguo, Zhou Mengguang, Kato Kenjiro, Asanuma Hiroyuki
机构信息
Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya, 464-8603, Japan.
出版信息
ACS Synth Biol. 2013 Apr 19;2(4):194-202. doi: 10.1021/sb300120n. Epub 2013 Feb 22.
We demonstrated the generality of a strategy for photoswitching the activity of functional oligonucleotides by modulating their topological structure. Our strategy was proved to be versatile because it can be used to photoregulate functional oligonucleotides, e.g., ribozymes and DNAzymes, which have two binding arms and a catalytic loop. Repeated reversible photoregulation of RNA cleavage by a ribozyme or a DNAzyme was achieved by attaching two photoresponsive strands, artificial oligomers involving azobenzene moieties and nucleobases capable of forming a duplex as the supraphotoswitch. Individual strands were attached to the 3' and 5' ends of a RNA-cleavage oligonucleotide. Thus, the topological structure of the ribozyme or DNAzyme was constrained, and RNA cleavage was greatly suppressed when the supraphotoswitch duplex formed (OFF state). In contrast, RNA cleavage resumed when the supraphotoswitch duplex dissociated (ON state). Light irradiation was used to repeatedly switch the supraphotoswitch between the ON and OFF states so that RNA cleavage activity could be efficiently photoregulated. Analysis of the regulatory mechanism showed that topological constraints suppressed the RNA cleavage by causing both structural changes at the catalytic site and lower binding affinity between the RNA substrates and the functional oligonucleotides.
我们展示了一种通过调节功能寡核苷酸的拓扑结构来光开关其活性的策略的通用性。我们的策略被证明是通用的,因为它可用于光调节具有两个结合臂和一个催化环的功能寡核苷酸,例如核酶和脱氧核酶。通过连接两条光响应链,即涉及偶氮苯部分和能够形成双链体的核碱基的人工寡聚物作为超光开关,实现了核酶或脱氧核酶对RNA切割的重复可逆光调节。单链分别连接到RNA切割寡核苷酸的3'和5'末端。因此,核酶或脱氧核酶的拓扑结构受到限制,当超光开关双链体形成时(关闭状态),RNA切割被大大抑制。相反,当超光开关双链体解离时(开启状态),RNA切割恢复。使用光照射在开启和关闭状态之间反复切换超光开关,从而可以有效地光调节RNA切割活性。对调节机制的分析表明,拓扑限制通过导致催化位点的结构变化以及RNA底物与功能寡核苷酸之间较低的结合亲和力来抑制RNA切割。