Regulation of Soluble guanylyl cyclase, the NO-receptor

由一氧化氮（NO）调节的细胞过程是生物学的许多方面的中心， 疾病，特别是在心血管系统和中枢及外周神经系统。尽管 尽管NO的重要性已被广泛认识，但对NO的调节机制却知之甚少 可溶性鸟苷酸环化酶（sGC）。sGC是一种含海因的异二聚体， 从底物GTP形成cGMP。当NO与血红素结合时，sGC被激活几次。 NO-cGMP信号级联被认为是血液调节的关键因素， 压力、突触可塑性和抑制血小板聚集。 拟议的研究旨在了解sGC调节机制的结构基础， 鉴定其活性调节剂： 1)我们最近的工作表明，sGC含有一个变构调节位点。我们试图找出残留物， 决定了所提出的变构位点的结构和性质。在腺苷酸环化酶同源性的指导下， 我们进行了突变分析，确定了两个亚基之间相互作用的特定区域， 似乎是介导变构激活的。我们将通过生物化学研究来描述这些突变体的特征 与分子建模相结合。 2)我们实验室和其他实验室最近的工作表明，sGC存在内源性调节因子。 我们已经发现但尚未鉴定一种新的内源性激活剂。我们将确定这种激活剂， 屏幕为他人。 3)野生型和突变体sGC将用于测试新生成的化学文库，该化学文库来源于 合成活化剂YC-1。活性化合物和sGC将用作分子建模的模板。 该模型与构效关系研究相结合，将用于生成详细的 关于NO-cGMP信号通路的生理调节的可检验的假设。 了解sGC的调节机制，并确定调节 揭示了某些类型的高血压、动脉粥样硬化的分子基础

The cellular processes that are regulated by nitric oxide (NO) are central to many aspects of biology and disease, particularly in the cardiovascular system and the central and peripheral nervous systems. Despite the widely recognized importance of NO, little is known about the mechanism of regulation of the NO receptor, the soluble guanylyl cyclase (sGC). sGC is a heine-containing heterodimer that catalyzes the formation of cGMP from the substrate GTP. Upon binding of NO to the heme, the sGC is activated several hundred-fold and it is thought that the NO-cGMP signaling cascade is a key player in regulation of blood )ressure, synaptic plasticity and inhibition of platelet aggregation. The proposed studies seek to understand the structural basis of mechanisms of regulation of the sGC and to identify modulators of its activity: 1) Our recent work suggests that sGC contains an allosteric regulatory site. We seek to identify residues that dictate the structure and nature of the proposed allosteric site. Guided by homology with adenylyl cyclases, we conducted a mutational analysis that identifies specific regions of interactions between the two subunits that seem to mediate allosteric activation. We shall characterize these mutants by biochemical studies integrated with molecular modeling. 2) Recent work from our laboratory and others, suggests that there is an endogenous regulator for the sGC. We have discovered but not yet identified a novel endogenous activator. We will identify this activator and screen for others. 3) The wild-type and mutants sGC will be used to test a newly generated chemical library derived from a synthetic activator, YC-1. Active compounds and sGC will be used as templates for molecular modeling. This modeling combined with structure-activity relationship studies will be used to generate detailed and testable hypotheses regarding the physiological modulation of the NO-cGMP signaling pathway. Understanding the mechanisms of regulation of sGC and identifying regulatory uncovering the molecular basis of some types of hypertension, atherosclerosis