论文标题
质量分辨的电子圆二色性离子光谱法
Mass-Resolved Electronic Circular Dichroism Ion Spectroscopy
论文作者
论文摘要
DNA和蛋白质是手性的：它们的三维结构不能与镜像相叠加。圆形二分色谱法广泛用于表征手性化合物，但是在混合物的情况下，很难进行数据解释。我们首次记录了在质谱仪中分离的DNA螺旋的电子圆形二分法光谱。我们具有各种二级结构为负离子，用激光照射它们的电泛光的富含鸟嘌呤的链，并测量了左右圆极化光之间电子光检查效率的差异。重建的圆二色性离子光谱类似于溶液，从而使我们能够分配DNA螺旋拓扑。直接在生物分子离子上测量圆二色性的能力扩大了质谱的能力来进行结构分析。
DNA and proteins are chiral: their three-dimensional structure cannot be superimposed with its mirror image. Circular dichroism spectroscopy is widely used to characterize chiral compounds, but data interpretation is difficult in the case of mixtures. We recorded for the first time the electronic circular dichroism spectra of DNA helices separated in a mass spectrometer. We electrosprayed guanine-rich strands having various secondary structures as negative ions, irradiated them with a laser, and measured the difference in electron photodetachment efficiency between left and right circularly polarized light. The reconstructed circular dichroism ion spectra resemble the solution ones, thereby allowing us to assign the DNA helical topology. The ability to measure circular dichroism directly on biomolecular ions expands the capabilities of mass spectrometry for structural analysis.
