Small molecule-linked programmable DNA for washing-free imaging of cell surface biomarkers
Small molecule-linked programmable DNA for washing-free imaging of cell surface biomarkers
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小分子连接的可编程 DNA 用于细胞表面生物标志物的免清洗成像
DOI：
10.1016/j.talanta.2018.07.091
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发表时间：
2018-12-01
期刊：
影响因子：
6.1
通讯作者：
Jiang, Jian-Hui
中科院分区：
文献类型：
--
作者：
Huang, Du-Juan;Wu, Zhan;Jiang, Jian-Hui
细胞膜中特异性生物标志物的检测对于细胞生物学和疾病治疗诊断学至关重要。在这里，我们开发了一种通用的终端保护检测策略，用于使用具有可编程信号序列的小分子连接的DNA对细胞表面蛋白进行免清洗定量和成像。DNA探针被设计为在3'端连接小分子配体以特异性识别细胞表面蛋白，并在5'端连接可编程信号序列以递送可检测的响应。小分子配体与靶蛋白的结合能够保护DNA探针免受核酸外切酶I介导的降解，使表面结合探针保持完整，而非结合探针降解。因此，该策略允许通过选择性保护的信号序列免洗涤检测细胞表面蛋白。基于核酸外切酶I能够淬灭银纳米团簇（AgNC）的荧光的新发现，通过编程信号序列为过氧化物酶样DNA酶、靶向DNA的定量聚合酶链反应（qPCR）和形成DNA模板的AgNC，我们可以将该策略发展成用于细胞表面蛋白的比色检测、qPCR定量和荧光成像的通用平台。使用叶酸连接的DNA探针检测肿瘤细胞表面上的叶酸受体来证明该平台。结果表明，该策略能够高度选择性和灵敏地检测肿瘤细胞以及定量和定位细胞上的膜蛋白，这意味着其在基于膜蛋白的生物医学和临床应用中的潜力。
Detection of specific biomarkers in cell membranes is critical for cell biology and disease theranostics. Here we develop a versatile terminal protection assay strategy for wash-free quantification and imaging of cell surface proteins using small molecule-linked DNA with programmable signal sequences. DNA probes are designed to link to a small molecule ligand at 3' end for specific recognition of the cell surface protein and a programmable signal sequence at 5' terminal for delivering detectable responses. Binding of the small molecule ligand to target protein enables protection of the DNA probes from exonuclease I mediated degradation, leaving the surface binding probes intact while the non-binding probes degraded. This strategy thus allows wash-free detection of the cell surface protein via the selectively protected signal sequence. By programming the signal sequences as peroxidase-like DNAzyme, quantitative polymerase chain reaction (qPCR) targeting DNA and Ag nanoclusters (AgNCs) forming DNA template based on our new finding that the exonuclease I is able to quench the fluorescence of AgNCs, we can develop this strategy into a versatile platform for colorimetric detection, qPCR quantification and fluorescence imaging of the cell surface protein. This platform is demonstrated using a folate-linked DNA probe for folate receptor detection on tumor cell surface. The results revealed that this strategy enables highly selective and sensitive detection of the tumor cells as well as quantification and localization of the membrane protein on the cells, implying its potential in membrane protein based biomedical and clinical applications.