STRUCTURE ACTIVITY RELATIONSHIPS IN CADPR

描述：细胞内钙的释放(钙信号) 在调节细胞功能方面起着基础性作用。环腺苷 二磷酸核糖(Cadpr)是一类小分子磷酸盐。 已知会导致钙释放，最近的证据表明cADPR的作用 在调节胰岛素分泌、糖尿病、免疫抑制、细胞 周期停滞和受精。使用cadpr和类似物的研究 阐明了这一信号通路的一部分，但相互作用的细节 CADPR、cADPR类似物和它们的同源蛋白之间的关系尚不清楚。而当 已经报道了cADPR本身的一些溶液结构特征， 对模拟溶液结构知之甚少，对模拟溶液结构更是知之甚少 相关cADPR结合蛋白复合体的结构。此应用程序 建议建立cADPR的结构活性关系。至 实现这一点，将合理地设计和合成cADPR类似物，以便 它们在溶液中的构象行为将在定义的、可预测的、 和可量化的时尚。结构修改包括改变 核糖羟基构型，系统取代羟基 含氟组，腺嘌呤部分外围的改变，以及 碳环(环戊烷)和腺嘌呤扩环的制备 类比。氟取代的类似物特别重要，就像氟一样 已知对糖构象有显著但可预测的影响。 对高质量核磁共振数据的分析将使糖的测定成为可能 构象、它们的相对种群和糖-磷酸骨架 扭角(伪旋分析)。一旦解决方案结构具有 一旦确定，将对类似物进行钙释放活性测试 以建立结构-活性关系。最后，从同位素角度来看 将准备标记的cADPR和类似物，以便以前无法访问 结构特征(例如糖苷扭转角)和 立体电子效应在糖、骨架和腺嘌呤之间的传递 基地就能显露出来。

DESCRIPTION: Release of calcium from intracellular stores (calcium signaling) plays a fundamental role in regulating cellular function. Cyclic adenosine diphosphate ribose (cADPR) is one of a family of small molecule phosphates known to cause calcium release, and recent evidence points to a role for cADPR in the regulation of insulin secretion, diabetes, immune suppression, cell cycle arrest, and fertilization. Studies using cADPR and analogs have elucidated parts of this signaling pathway, but the details of the interactions between cADPR, cADPR analogs, and their cognate proteins remain unclear. While some of the solution structural features of cADPR itself have been reported, very little is known about the analog solution structures and even less about the structure of the relevant cADPR-binding protein complexes. This application proposes to establish the structure activity relationships for cADPR. To achieve this, cADPR analogs will be rationally designed and synthesized so that their conformation behavior in solution will vary in a defined, predictable, and quantifiable fashion. The structural modifications include altering the ribose hydroxyl group configurations, systematically replacing the hydroxyl groups with fluorine, alterations to the periphery of the adenine moiety, and the preparation of carbocyclic (cyclopentane) and adenine ring-extended analogs. The fluorosubstituted analogs are especially important, as fluorine is known to have pronounced yet predictable effects on sugar conformations. Analysis of high quality NMR data will allow determination of the sugar conformations, their relative populations, and the sugar-phosphate backbone torsion angles (pseudorotational analysis). Once the solution structures have been determined, the analogs will be tested for Ca2+-releasing activity in order to establish the structure-activity relationships. Finally, isotopically labeled cADPR and analogs will be prepared so that previously inaccessible structural features (e.g. glycosidic torsion angles) and the extent of transmission of stereoelectronic effects between sugars, backbone and adenine base can be revealed.