含有鸟嘌呤（G）和胞嘧啶（C）重复的核酸序列能相互作用形成双螺旋结构，还可以自组装形成G-和C-四链体结构。G-和C四链体的形成不仅具有特殊的生物学意义，而且在抗肿瘤和抗艾滋病药物设计及核酸纳米结构构建中发挥重要作用。然而，30多万种富含G的序列存在于人类基因中所形成的结构形貌，以及如何利用核酸序列自由地构建核酸纳米材料，这一直是没有解决的问题。在这项研究中，我们将建立以质谱分析技术为主结合有其他分析手段的方法，研究已知G-和C-四链体结构特征，建立结构标签组；结合序列碱基化学修饰和碱基置换等研究方法，研究核酸碱基间相互作用；基于这些研究结果，建立结构-序列-结构标签之间的联系，为预测人类基因形成的结构及自由构建核酸纳米分子奠定基础。

DNA sequences with repeating guanine (G) or/and cytosine (C) can interact each other forming double helix, and also can self-assemble forming G- or C-quadruplexes. The formations of G- and C-quadruplexes are not only biologically significant but also have potential applications in drug designs of anti-cancer and anti-HIV as well as in construction of nucleic acid supramolecules. However, this has been challenges on how to predict individual structural topology formed by each of over 300 thousands of various G- or C-repeating sequences in human gene, and how to comprehensively modulate the design of nucleic acid supramolecules. In this work, we will develop a mass spectrometric based method which includes other techniques to study well resolved structures of G- and C-quadruplexes, and to obtain characteristic spectrum tags of the particular structure. These tags combined with base interaction information obtained by studies of base chemical modification and base modifications in the sequences are used to build correlations of structure-sequence-tags. Our goal is to establish an effective method for directing structural prediction and supramolecule construction.