Investigation of the formation of binary or ternary comlexes of quadruplex-forming DNA sequences of the insulin-linked polymorphic region (ILPR) with organic ligands and insulin

对核酸、蛋白质和小配体之间相互作用的研究有助于对生化过程的基本理解，因此，从长远来看，有助于制定急性或慢性疾病的治疗策略。特别是四重体DNA的结构和功能越来越受到人们的关注。富含鸟嘌呤的DNA序列通过鸟嘌呤四重奏的组装和堆叠形成四重结构，它们被认为是生理过程的相关中间体和选择性药物的有希望的靶点。在这种情况下，胰岛素连锁多态区（ILPR）代表了一个显著的富含g的序列，位于人类胰岛素基因的启动子区域，其生理功能部分可以通过其支持形成四重结构来解释。研究表明，配体的结合可能影响含四联体DNA序列的结构和生物活性；然而，这方面在ILPR-DNA的研究中一直被忽视。因此，本研究项目旨在首次系统地研究已知和新开发的配体与四联体形成的ILPR序列的相互作用。通过这种方法，可以识别选择性的ILPR-DNA配体，并评估那些影响ILPR-DNA中配体诱导的四重结构稳定性和由此产生的结构变化的因素。该项目的另一个目标是检查胰岛素与ILPR-DNA的关联，因为所有文献数据都指向这种相互作用的生物学功能。特别是，我们将研究配体是否通过形成三元复合物来增加胰岛素- dna相互作用的强度，或者是否抑制复合物的形成，因为这两种事件都可能对生物活性产生影响。此外，在所研究的配体中鉴定出衍生物，这些衍生物可以用作荧光探针，通过发射发光效应有效地检测ILPR-DNA中的四重结构。

Studies of the interactions between nucleic acids, proteins and small ligands contribute significantly to the fundamental understanding of biochemical processess and hence - in the long term - to the development of strategies for the therapy of acute or chronic diseases. In particular, the structures and functions of quadruplex DNA attract increasing attention. Quadruplex structures are formed in guanine-rich DNA sequences through the assembly and stacking of guanine quartets, and they are proposed to be relevant intermediates in physiological processes and promising targets for selective drugs. In this context the insulin-linked polymorphic region (ILPR) represents a remarkable G-rich sequence that is located in the promoter region of the human insulin gene und whose physiological function is explained in part by its proponsity to form quadruplex structures. It is established that the association of ligands may affect the structures and biological activity of quadruplex-containing DNA sequences; however, this aspect has been neglected so far in studies of ILPR-DNA. Therefore this research project aims at the first systematic investigation of the interactions of known and newly developed ligands with quadruplex-forming ILPR sequences. With this approach selective ILPR-DNA ligands shall be identified and those factors will be assessed that govern the ligand-induced stabilization of quadruplex structures in ILPR-DNA and the resulting structural changes. Another goal of the project is the examination of the association of insulin with ILPR-DNA, because all literature data point to a biological function of this interaction. In particular, it will be examined whether a ligand increases the strength of the insulin-DNA interaction by the formation of a ternary complex or whether it inhibits the complex formation, as both events may have an effect on the biological activity. In addition, derivatives shall be identified amongst the investigated ligands that may be used as fluorescent probes for efficient detection of quadruplex structures in ILPR-DNA by emission light-up effects.