Nano-Analysis of DNA Conformation Changes Induced by Transcription Factor Complex Binding Using Plasmonic Nanodimers
Nano-Analysis of DNA Conformation Changes Induced by Transcription Factor Complex Binding Using Plasmonic Nanodimers
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DOI：
10.1021/nn403625s
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发表时间：
2013-12-01
期刊：
影响因子：
17.1
通讯作者：
Inouye, Yasushi
中科院分区：
文献类型：
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作者：
Morimura, Hiroyuki;Tanaka, Shin-Ichi;Inouye, Yasushi
一对金纳米颗粒或金纳米二聚体的等离子体共振波长与两个纳米颗粒之间的差距距离成反比地增加。利用这一特性，我们进行了纳米级的测量，由转录因子结合诱导的DNA构象变化。金纳米颗粒由双链DC 5 DNA桥接，该DNA包括转录因子SOX 2和PAX 6的结合序列，其在DC 5增强子序列上相互作用并激活转录。由SOX 2结合的金纳米二聚体将等离子体共振波长从586.8 nm移动到604.1 nm，表明SOX 2结合诱导DNA弯曲。当SOX 2与PAX 6在DC 5上形成三元复合物时，等离子体共振波长显示出进一步偏移至611.6nm，表明DC 5序列中的额外弯曲。此外，我们研究了SOX 2和PAX 6在DC 5-con序列上诱导的DNA构象变化，DC 5-con序列是DC 5的PAX 6结合区的共有序列，其增强PAX 6结合，但同时破坏SOX 2-PAX 6依赖的转录激活。当DC 5中的PAX 6结合序列改变为DC 5-con时，等离子体共振波长移动少得多至606.5 nm，这与单独的SOX 2的603.9 nm更可比。这些结果表明，SOX 2-PAX 6共结合诱导DC 5 DNA的大的构象变化。
The plasmon resonant wavelength for a pair of gold nanoparticles, or gold nanodimer, increases inversely with the gap distance between the two nanoparticles. Taking advantage of this property, we performed nanoscale measurements of DNA conformation changes induced by transcription factor binding. Gold nanoparticles were bridged by double-stranded DC5 DNA that included binding sequences for the transcription factors SOX2 and PAX6, which interact on the DC5 enhancer sequence and activate transcription. The gold nanodimers bound by SOX2 shifted the plasmon resonant wavelength from 586.8 to 604.1 nm, indicating that SOX2 binding induces DNA bending. When the SOX2 formed a ternary complex with PAX6 on DC5, the plasmon resonant wavelength showed a further shift to 611.6 nm, indicating additional bending in the DC5 sequence. Furthermore, we investigated DNA conformation changes induced by SOX2 and PAX6 on the DC5-con sequence, which is a consensus sequence of DC5 for the PAX6 binding region that strengthens the PAX6 binding but at the same time disrupts SOX2–PAX6-dependent transcriptional activation. When the PAX6 binding sequence in DC5 was altered to DC5-con, the plasmon resonant wavelength shifted much less to 606.5 nm, which is more comparable to the 603.9 nm by SOX2 alone. These results demonstrate that SOX2–PAX6 cobinding induces a large conformation change in DC5 DNA.