Molecular mechanisms in morpholino-DNA surface hybridization.
Molecular mechanisms in morpholino-DNA surface hybridization.
复制标题
吗啉代-DNA 表面杂交的分子机制。
DOI：
10.1021/ja100881a
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发表时间：
2010-07-21
影响因子：
15
通讯作者：
Levicky, Rastislav
中科院分区：
文献类型：
--
作者：
Gong, Ping;Wang, Kang;Liu, Yatao;Shepard, Kenneth;Levicky, Rastislav
人工合成的核酸模拟物为重新设计与天然DNA或RNA杂交的特异性和亲和力提供了机会。这种重新设计对于诊断应用非常有意义，因为它可以在相互竞争的背景下增强所需的信号。这份报告比较了DNA分析物链与吗啉(MO)的杂交，后者是不带电荷的核酸模拟物，与相应的DNA-DNA案例在溶液中和表面上进行了比较。在溶液中，与DNA-DNA杂交相比，MO-DNA杂交与反离子浓度无关。在表面，当固定化的MO或DNA“探针”链从溶液中与互补的DNA“靶标”杂交时，MO-DNA和DNA-DNA过程都取决于离子强度，但表现出本质上的不同行为。在较低的离子强度下，MO-DNA表面杂交表现出动力学限制的特征，当杂交探针位置之间的间隔变得与目标尺寸相当时，而DNA-DNA表面杂交的范围与表面(Donnan)电位的积累施加的限制是一致的。在静电效应较弱的条件下，这两个过程在高离子强度下也有根本的不同。在这里，对于同样拥挤的表面条件，探针覆盖范围的变化对MO-DNA的影响比对DNA-DNA杂交的影响要小得多。这些不同的观察结果与MO单分子膜的结构模型相一致，在该模型中，MO-DNA双链分离到缓冲液界面，而未杂交的探针定位在固体载体附近。提出了在表面杂交应用中使用不带电荷的DNA类似物的一般前景，其中还包括多肽核酸(PNA)等化合物。
Synthetic nucleic acid mimics provide opportunity for redesigning the specificity and affinity of hybridization with natural DNA or RNA. Such redesign is of great interest for diagnostic applications where it can enhance the desired signal against a background of competing interactions. This report compares hybridization of DNA analyte strands with morpholinos (MOs), which are uncharged nucleic acid mimics, to the corresponding DNA-DNA case in solution and on surfaces. In solution, MO-DNA hybridization is found to be independent of counterion concentration, in contrast to DNA-DNA hybridization. On surfaces, when immobilized MO or DNA “probe” strands hybridize with complementary DNA “targets” from solution, both the MO-DNA and DNA-DNA processes depend on ionic strength but exhibit qualitatively different behaviors. At lower ionic strengths, MO-DNA surface hybridization exhibits hallmarks of kinetic limitations when separation between hybridized probe sites becomes comparable to target dimensions, whereas extents of DNA-DNA surface hybridization are instead consistent with limits imposed by buildup of surface (Donnan) potential. The two processes also fundamentally differ at high ionic strength, under conditions when electrostatic effects are weak. Here, variations in probe coverage have a much diminished impact on MO-DNA than on DNA-DNA hybridization for similarly crowded surface conditions. These various observations agree with a structural model of MO monolayers in which MO-DNA duplexes segregate to the buffer interface while unhybridized probes localize near the solid support. A general perspective is presented on using uncharged DNA analogues, which also include compounds such as peptide nucleic acids (PNA), in surface hybridization applications.
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影响因子：
12.6
作者：
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通讯作者：
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作者：
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