State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, PR China.
Biosens Bioelectron. 2013 Dec 15;50:180-5. doi: 10.1016/j.bios.2013.06.041. Epub 2013 Jun 29.
A novel label-free DNAzyme molecular beacon (MBzyme) strategy was for the first time developed for colorimetric amplification detection of target nucleic acids. The MBzyme, which is designed to contain peroxidase-mimicking DNAzyme that is locked by a common hairpin, was engineered to form a catalytically active MBzyme through hybridizing with the target p53 DNA. The MBzyme is a multifunctional label-free probe that can act as the target recognition element, catalytic DNAzyme and the primer of polymerization. The target p53 DNA hybridization can induce the isothermal circular strand-displacement polymerization even without any chemical modification and other DNA sequences. This unique amplifying strategy leads to the generation of multiple numbers of active MBzyme molecules even if one hybridization event occurs, achieving a dynamic range of seven orders of magnitude and giving a detection limit down to 25 fM which is 3-5 orders of magnitude lower than those of related literature reports. These achievements might be helpful in the design of highly efficient enhancers for G-quadruplex-hemin DNAzymes to be applied on the fundamental research, biotechnology, and biomedical diagnosis.
一种新型的无标记 DNA 酶分子信标 (MBzyme) 策略被首次开发用于目标核酸的比色扩增检测。该 MBzyme 设计为包含过氧化物酶模拟 DNA 酶，该酶被一个常见的发夹锁住，通过与目标 p53 DNA 杂交而形成具有催化活性的 MBzyme。MBzyme 是一种多功能的无标记探针，可作为靶标识别元件、催化 DNA 酶和聚合引物。目标 p53 DNA 杂交可以诱导等温循环链置换聚合，即使没有任何化学修饰和其他 DNA 序列。这种独特的扩增策略导致即使发生一次杂交事件也能产生多个活性 MBzyme 分子，实现了七个数量级的动态范围，并将检测限降低至 25 fM，比相关文献报道低 3-5 个数量级。这些成就可能有助于设计用于 G-四链体-血红素 DNA 酶的高效增强子，应用于基础研究、生物技术和生物医学诊断。
