Un-uniform binding of single-stranded DNA binding proteins on to hybrids of single-stranded DNA and single-walled carbon nanotubes studied by atomic force microscopy in air and in liquid
Un-uniform binding of single-stranded DNA binding proteins on to hybrids of single-stranded DNA and single-walled carbon nanotubes studied by atomic force microscopy in air and in liquid
复制标题
通过原子力显微镜在空气和液体中研究单链 DNA 结合蛋白与单链 DNA 和单壁碳纳米管的杂交体的不均匀结合
DOI：
10.1016/j.apsusc.2015.12.144
复制
发表时间：
2016
影响因子：
6.7
通讯作者：
Katsuki Izumi
中科院分区：
文献类型：
--
作者：
Kazuo Umemura;Kei Ishizaka;Daisuke Nii;Katsuki Izumi
使用原子力光谱 (AFM)，我们观察到空气和水溶液中含有或不含蛋白质分子的单链 DNA (ssDNA) 和单壁碳纳米管 (SWNT) 的杂化物。这是通过 AFM 分析溶液中蛋白质的 ssDNA-SWNT 杂交体的第一份报告。在没有蛋白质的情况下，ssDNA-SWNT 杂化物的高度在空气和液体中分别为 1.1 ± 0.3 nm 和 2.4 ± 0.6 nm，表明 ssDNA 分子在 SWNT 表面上采用了柔性结构。在存在单链 DNA 结合 (SSB) 蛋白的情况下，混合体在空气和液体中的高度分别增加至 6.4 ± 3.1 nm 和 10.0 ± 4.5 nm。 AFM 图像清楚地显示了 SSB 蛋白与 ssDNA-SWNT 杂交体的结合。 SSB-ssDNA-SWNT 杂化物的形态不均匀，特别是在水溶液中。通过沿着每个杂种的长轴的横截面分析来定量估计杂种高度的方差。 SSB-ssDNA-SWNT 杂交体表现出比 ssDNA-SWNT 杂交体大得多的方差。
Using atomic force spectroscopy (AFM), we observed hybrids of single-stranded DNA (ssDNA) and single-walled carbon nanotubes (SWNTs) with or without protein molecules in air and in an aqueous solution. This is the first report of ssDNA–SWNT hybrids with proteins in solution analyzed by AFM. In the absence of protein, the height of the ssDNA–SWNT hybrids was 1.1 ± 0.3 nm and 2.4 ± 0.6 nm in air and liquid, respectively, suggesting that the ssDNA molecules adopted a flexible structure on the SWNT surface. In the presence of single-stranded DNA binding (SSB) proteins, the heights of the hybrids in air and liquid increased to 6.4 ± 3.1 nm and 10.0 ± 4.5 nm, respectively. The AFM images clearly showed binding of the SSB proteins to the ssDNA–SWNT hybrids. The morphology of the SSB–ssDNA–SWNT hybrids was non-uniform, particularly in aqueous solution. The variance of hybrid height was quantitatively estimated by cross-section analysis along the long-axis of each hybrid. The SSB–ssDNA–SWNT hybrids showed much larger variance than the ssDNA–SWNT hybrids.