Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem, 91904 Israel.
Anal Chem. 2009 Nov 1;81(21):9114-9. doi: 10.1021/ac901773b.
Engineered nucleic acid hairpin structures are used for the amplified analysis of low-molecular-weight substrates (adenosine monophosphate, AMP) or proteins (lysozyme). The hairpin structures consist of the anti-AMP or antilysozyme aptamer units linked to the horseradish peroxidase (HRP)-mimicking DNAzyme sequence. The HRP-mimicking DNAzyme sequence is protected in a "caged", inactive structure in the stem regions of the respective hairpins, whereas the loop regions include a part of the respective aptamer sequence. The opening of the hairpins by the analytes, AMP or lysozyme, through the formation of the respective analyte-aptamer complexes, results in the self-assembly of the active HRP-mimicking DNAzyme. The DNAzyme catalyzes the H(2)O(2)-mediated oxidation of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(2-)) to the colored ABTS(*-), thus providing the amplified optical detection of the respective analytes. The engineered aptamer-DNAzyme hairpin structures reveal significantly improved analytical performance, as compared to analogous fluorophore-quencher-labeled hairpins.
经工程化设计的核酸发夹结构被用于低分子量底物（腺苷一磷酸，AMP）或蛋白质（溶菌酶）的放大分析。发夹结构由与辣根过氧化物酶（HRP）模拟 DNA 酶序列相连的抗 AMP 或抗溶菌酶适体单元组成。HRP 模拟 DNA 酶序列在各自发夹的茎区中以“笼状”、非活性结构的形式被保护，而环区则包含各自适体序列的一部分。分析物 AMP 或溶菌酶通过形成各自的分析物-适体复合物来打开发夹，导致活性 HRP 模拟 DNA 酶的自组装。DNA 酶催化 H(2)O(2)介导的 2,2'-联氮双（3-乙基苯并噻唑啉-6-磺酸）（ABTS(2-))的氧化为有色 ABTS(*-)，从而提供各自分析物的放大光学检测。与类似的荧光团-猝灭剂标记的发夹相比，经工程化设计的适体-DNA 酶发夹结构显示出显著改善的分析性能。
