Selection of fluorescent aptamer beacons that light up in the presence of zinc
Selection of fluorescent aptamer beacons that light up in the presence of zinc
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DOI：
10.1007/s00216-007-1735-8
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发表时间：
2008-02-01
影响因子：
4.3
通讯作者：
Ellington, Andrew D.
中科院分区：
文献类型：
--
作者：
Rajendran, Manjula;Ellington, Andrew D.
为了产生在金属锌存在的情况下可以经历可逆构象变化的核酸生物传感器，将单链DNA的随机序列池固定在寡核苷酸亲和柱上。在存在锌的情况下，那些经历构象变化的物质从柱中释放、收集并扩增。一系列的负选择和正选择完善了所选适体信标的金属特异性。由于适体信标含有荧光团，而结合的寡核苷酸含有猝灭剂，因此锌结合也会导致荧光增加。选定的信标之一 Zn-6m2 在低微摩尔范围内结合锌，发出剂量依赖性荧光信号，并显示锌结合荧光增加约六倍。虽然观察到与镉的一些交叉反应，但仍然应该证明可以使用新颖的选择方法来生成和调整各种可逆金属生物传感器的特异性。这种生物传感器有可能用于连续监测环境样品中的金属。
In order to generate nucleic acid biosensors that could undergo a reversible conformation change in the presence of the metal zinc, a random sequence pool of single-stranded DNA was immobilized on an oligonucleotide affinity column. In the presence of zinc, those species that underwent a conformational change were released from the column, collected, and amplified. A series of negative and positive selections refined the metal specificity of the selected aptamer beacons. Since the aptamer beacons contained a fluorophore, while the bound oligonucleotide contained a quencher, zinc binding also resulted in an increase in fluorescence. One of the selected beacons, Zn-6m2, bound zinc in the low micromolar range, gave a dose-dependent fluorescence signal, and showed an approximately sixfold increase in fluorescence on zinc binding. While some cross-reactivity with cadmium was observed, it should nonetheless prove possible to use the novel selection method to generate and tune the specificity of a variety of reversible metal biosensors. Such biosensors could potentially be used for continuous monitoring of metals in environmental samples.