AFM characterization of single strand-specific endonuclease activity on linear DNA.
AFM characterization of single strand-specific endonuclease activity on linear DNA.
复制标题
线性 DNA 上单链特异性核酸内切酶活性的 AFM 表征。
作者：
K. Umemura;F. Nagami;T. Okada;R. Kuroda
核酸酶对有切口和无切口双链DNA的特异性已经使用原子力显微镜（AFM）表征。我们已经发现，原子力显微镜具有优势，在表征核酸酶消化通常的宏观分析，如蔗糖梯度离心或电泳。特别地，检测到由非特异性消化产生的短DNA片段，因此，揭示了消化的DNA的真实长度分布。提出了一种简单的数值计算方法，根据AFM图像估计每个DNA分子的切口位点数。
The specificity of nucleases for nicked and un-nicked double-stranded DNA has been characterized using atomic force microscopy (AFM). We have found that AFM has advantages over the usual macroscopic analyses, such as sucrose gradient centrifugation or electrophoresis, in characterizing nuclease digestion. In particular, short DNA fragments resulting from non-specific digestion were detected and, thus, the true length distribution of digested DNA was revealed. A simple numerical method is proposed to estimate the number of nicked sites per DNA molecule based on AFM images.