RUI: Exploring Shape-selective Binding of the DNA Major Groove by Haiprin bis(diarylmethylene)Hydrazides

有了这个奖项，化学部门的生命过程化学项目资助了来自加州州立大学北岭分校的Thomas Minehan博士，研究一组发夹二芳基亚甲基肼化合物与DNA主槽结合的紧密程度，从而有可能提供控制基因表达的时间和水平的新工具。自然界的转录因子是一种蛋白质，它通过识别和结合双螺旋主槽中的DNA序列来控制细胞中基因的开启时间。因此，与转录因子结合竞争的化合物可以用来控制可能失控的基因。在这里构建的分子是为了识别DNA中被加宽的区域，模仿蛋白质结合时双螺旋的形状。开发选择性识别DNA形状的分子代表了化学和化学生物学中重要的新探索方向。这方面的成功可能会导致一种新的定制合成药物来调节基因表达。该研究为本科生和研究生提供了有机化学和生物化学界面的宝贵训练。此外，正在开发新的课程和教学资源，以增加非理科生对化学相关领域的欣赏。目前迫切需要开发用于序列特异性主凹槽粘结剂的新型化学支架。肽系二芳基亚甲基肼是空间上体积大的小分子，带正电的二甲氨基之间有一定距离。改变这些分子的系链长度和芳族表面积，可以设计出在投射的正电荷之间具有良好定义距离的配体，以便与扩展的DNA主槽两侧的带负电荷的磷酸基团接触。合成了四种具有不同N-N跨度的肼配体，并利用荧光插层置换法和等温滴定量热法评估了它们的DNA结合亲和力和序列选择性。这些研究，连同选定dna -配体复合物的x射线晶体学数据，将用于获得序列选择性结合的最佳配体结构。最后，电泳迁移率转移试验将被用来评估配体选择性抑制转录因子与其靶核酸序列结合的能力，从而揭示这类化合物的治疗和生物技术前景。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemistry of Life Processes Program of the Chemistry Division is funding Dr. Thomas Minehan from California State University-Northridge to investigate how tightly a set of hairpin bis(diarylmethylene)-hydrazide compounds bind to the DNA major groove and thereby potentially provide new tools to control when and at what levels genes are expressed. Nature's transcription factors are proteins that control when genes are turned on in cells by recognizing and binding DNA sequences in the major groove of the double-helix. Compounds that compete against transcription factor binding can thus be used to control genes that may be out of control. The molecules being constructed herein are to recognize regions in the DNA that are widened, mimicking the shape of the double-helix when proteins bind. Efforts to develop molecules that recognize DNA shape-selectively represent important new exploratory directions in chemistry and chemical biology. Success here could lead to a new class of tailored synthetic agents that modulate gene expression. The research provides valuable training at the interface of organic and biological chemistry to both undergraduate and graduate students. In addition, a new course and teaching resources are being developed to increase the appreciation of chemistry-related fields by non-science students.There is great need to develop new chemical scaffolds for sequence-specific major-groove binders. Peptide-tethered bis(diarylmethylene)-hydrazides are sterically bulky small molecules with defined distances between positively charged dimethylamino groups. Varying the tether length and aromatic surface area of these molecules allows the design of ligands with well defined distances between the projected positive charges so as to contact the negatively charged phosphate groups on opposite sides of expanded DNA major groove. Four hydrazide ligands possessing varying N-N spans will be synthesized and their DNA binding affinity and sequence selectivity evaluated using fluorescent intercalator displacement assays and isothermal titration calorimetry. These studies, together with X-ray crystallographic data on select DNA-ligand complexes, will be used to achieve optimal ligand structures for sequence-selective binding. Finally, an electrophoretic mobility shift assay is to be utilized to assess the ability of the ligands to selectively inhibit the binding of transcription factors to their target nucleic acid sequences, thus shedding light on the therapeutic and biotechnological promise of this class of compounds.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.