CAJ | 학술논문

对鸟嘌呤碱基G重复序列之间连接环结构对G-四链体形成的影响进行了研究。发现在连接环较长,DNA链不易形成G-四链体的情况下,可以通过将环序列设计成双链结构的方式促进G-四链体的重新形成。这就为传感器的设计提供了一个新途径,即可以利用目标分子对环部双链的调节作用控制G-四链体DNA酶的活性。为证明这一点,在双链区域引入T-T碱基错配,破坏双链结构使DNA链不能形成G-四链体。Hg2+对T-T错配的稳定作用可以促进双链结构的形成,DNA链重新折叠成G-四链体,得到的G-四链体与氯化血红素( Hemin)结合后形成具有过氧化物酶活性的G-四链体DNA酶,据此构建了Hg2+传感器。利用此传感器可在10~700 nmol/L范围内实现Hg2+的定量检测,检出限为8.7 nmol/L。在此基础上,利用半胱氨酸可以将Hg2+从T-Hg2+-T碱基对上竞争下来的能力,设计了一种半胱氨酸的检测方法。此方法可以在20~600 nmol/L范围内实现半胱氨酸的定量检测,检出限为14 nmol/L。
대조표령감기G중복서렬지간련접배결구대G-사련체형성적영향진행료연구。발현재련접배교장,DNA련불역형성G-사련체적정황하,가이통과장배서렬설계성쌍련결구적방식촉진G-사련체적중신형성。저취위전감기적설계제공료일개신도경,즉가이이용목표분자대배부쌍련적조절작용공제G-사련체DNA매적활성。위증명저일점,재쌍련구역인입T-T감기착배,파배쌍련결구사DNA련불능형성G-사련체。Hg2+대T-T착배적은정작용가이촉진쌍련결구적형성,DNA련중신절첩성G-사련체,득도적G-사련체여록화혈홍소( Hemin)결합후형성구유과양화물매활성적G-사련체DNA매,거차구건료Hg2+전감기。이용차전감기가재10~700 nmol/L범위내실현Hg2+적정량검측,검출한위8.7 nmol/L。재차기출상,이용반광안산가이장Hg2+종T-Hg2+-T감기대상경쟁하래적능력,설계료일충반광안산적검측방법。차방법가이재20~600 nmol/L범위내실현반광안산적정량검측,검출한위14 nmol/L。
The effects of linking loop structure between guanine ( G) repeats on G-quadruplex formation were investigated. The results show that the unfavorable effects of long linking loops on G-quadruplex formation can be overcome by introducing double-stranded structures in linking loop regions. This finding provides a new way for sensor design. The activity of G-quadruplex DNAzyme can be tuned by utilizing target-mediated formation of double-stranded structures in loops. As an example, T-T mismatches are introduced in loops to destroy double-stranded structures. The stabilization of Hg2+ to T-T mismatches promotes the reformation of double-stranded structures. Correspondingly, the oligonucleotide folds into G-quadruplex, which binds with hemin to form peroxidase-like G-quadruplex DNAzyme. Hg2+ sensor is designed based on this principle. Using this method, Hg2+ quantitation is achieved in the concentration range of 10-700 nmol/L, with a detection limit of 8. 7 nmol/L. Cysteine will compete with T bases to bind with Hg2+, releasing Hg2+from T-Hg2+-T base pairs. Thus cysteine can also be quantified with this system in the concentration range of 20-700 nmol/L, with a detection limit of 14 nmol/L.