HEPARANOMICS: STRUCTURE-FUNCTION RELATIONSHIPS

描述（由申请人提供）：硫酸乙酰肝素（HS）在细胞表面和细胞外基质中大量表达，作为具有差异硫酸化模式、链长和链数的蛋白聚糖，导致大量结构特征。每条链同时与许多蛋白质相互作用，包括各种信号分子，形态发生素，受体等，并协调各种生物功能。它们的生物合成途径的调节已经开始阐明它们在斑马鱼、c.然而，由于缺乏有效的合成方法，再加上从动物模型中分离出的少量HS链，限制了我们对这些分子如何在分子水平上调节各种生理和病理过程的了解。该提议的中心假设是，具有保守关键基团的多个寡糖序列可能阐明相同的生物学反应，或者具有一组关键基团的给定寡糖序列可能阐明一种以上的生物学反应。确定这些关键基团及其空间距离将足以确定决定HS-蛋白质相互作用的规则。开发一个通用的酶促方法的快速组装HS的各种大小的应该允许我们测试我们的假设，并描绘规则，支配HS-蛋白质相互作用。我们建议构建寡糖库，并筛选它们与在心、肺和脑发育中起核心作用的各种生长因子和受体形成信号复合物的能力。在稳定同位素的帮助下，我们将开发新的结构生物学方法来阐明生物功能的关键基团。在合成ATIII结合位点中获得的知识将用于设计不同大小的HS库，这应该是定义所有相互作用蛋白质和阐明这种相互作用发生的化学规则的关键。这项研究为蛋白多糖的糖生物学研究奠定了坚实的基础。

DESCRIPTION (provided by applicant): Heparan sulfates (HS) are abundantly expressed on the cell surface and in the extracellular matrix as proteoglycans with differential sulfation pattern, chain length and number of chains leading to vast structural features. Each chain interacts simultaneously with numerous proteins including a variety of signaling molecules, morphogens, receptors, etc and orchestrates various biological functions. Modulation of their biosynthetic pathways has begun to shed light on their role in such model organisms as zebra fish, c. elegans, drosophila, etc. However, the lack of efficient synthetic approaches coupled with a small amount of HS chains isolated from animal models has limited our knowledge of how these molecules regulate various physiological and pathological processes at the molecular level. The central hypothesis of this proposal is that multiple oligosaccharide sequences with conserved critical groups may elucidate the same biological response or that a given oligosaccharide sequence with a set of critical groups may elucidate more than one biological response. Determining those critical groups and their spatial distance would be sufficient to determine the rules that dictate HS-protein interactions. Development of a general enzymatic approach for the rapid assembly of HS of various sizes should allow us to test our hypothesis and to delineate the rules that dictate HS-protein interactions. We propose to construct the oligosaccharide libraries and screen their ability to form signaling complex with various growth factors and receptors that play a central role in heart, lung and brain development. With the aid of stable isotopes, we will then develop novel structural biology approaches to elucidate the critical groups that attribute a biological function. The knowledge gained in synthesizing ATIII binding sites will be used in designing diverse size-based HS libraries that should be the key to defining all interacting proteins and elucidating the chemical rules by which such interactions take place. This proposed study should establish a firm foundation for the glycobiology of proteoglycans.