Heparin like Glycosaminoglycan Oligosaccharides

对于DNA(RNA)和蛋白质这两种主要的生物聚合物，主要的科学努力一直旨在了解序列是如何决定功能的。第三种主要的生物聚合物是多糖。类肝素糖胺聚糖(HLGAGs)是一类对重要生物现象有重要影响的多糖类化合物。HLGAGs与胚胎发育、血液凝结和新血管生长等重要过程密切相关。我们知道HLGAGs与蛋白质结合并影响其活性，从而影响细胞功能，但我们不知道HLGAGs如何执行其重要的生物学功能。部分问题是HLGAGs是复杂的分子，就其化学结构而言，比DNA或蛋白质更复杂。例如，一个由四个碱基组成的DNA分子可能有16个可能的序列，一个四个氨基酸的多肽可能有16万个可能的序列，而一个由四个单位组成的HLGAG可能有100多万个可能的序列！因此，目前在处理HLGAGs的化学复杂性方面有很大的困难，特别是因为缺乏分离纯HLGAGs并确定其结构的工具。我们实验室正在进行的研究旨在开发这样的工具，既要对HLGAG结构如何影响功能进行科学的理解，又要提供有关疾病干预的新靶点的信息，如肿瘤生长、转移和血管生成。最近，我们开发了一种快速测定生物相关HLGAG多糖的化学序列的技术。在这项拨款申请中，我们建议将我们的测序程序扩展到直接在芯片上完成活性HLGAG片段的分离和测序。我们称我们的过程为CAN-MS，它代表芯片非共价缔合质谱学。将几种方法结合到一个程序中将使我们能够快速有效地研究具有重要生物学活性的HLGAG，并有助于开发高通量、自动化的机器来回答重要的科学问题。我们建议解决的一个具体问题是HLGAG序列，它结合并促进内皮抑素的活性，内皮抑素是一种有效的内源性抗癌药物。DNA和蛋白质的类似技术包括基因芯片之类的东西，它们彻底改变了这些分子的研究。我们希望先进的技术，如OUT技术，将为HLGAG做同样的事情。

With DNA (RNA) and proteins, two major biopolymers, major scientific effort has been aimed at understanding how sequence dictates function. The third major biopolymer is the polysaccharides. One of the most important groups of polysaccharides, in term of its influence on important biological phenomena, are the heparin-like glycosaminoglycans (HLGAGs). HLGAGs are intimately involved in important processes like embryo development, blood clotting, and new vessel growth. We know that HLGAGs bind to proteins and affect their activity, thus influencing cell functions but we do not know how HLGAGs carry out their important biological functions. Part of the problem is that HLGAGs are complicated molecules, more complicated, in terms of their chemical structure, than either DNA or proteins. For instance, while a DNA molecule made of four bases can have 16 possible sequences and a four amino acid peptide can have 160,000 possible sequences, a HLGAG made of four units can potentially have over one million possible sequences! As such, there is a great deal of difficulty, at the present time, in handling the chemical complexity of HLGAGs, especially since there are a lack of tools to isolate pure HLGAGs and determine their structure. Ongoing research in our laboratory is aimed at developing such tools, both to develop a scientific understanding of how HLGAG structure impinges on function, and provide information on novel targets fir intervention in diseases, such as tumor growth, metastasis, and angiogenesis. Recently, we have developed a technique to rapidly determine the chemical sequence of biologically relevant HLGAG polysaccharides. In this grant application, we propose to extend our sequencing procedure to complete isolation and sequencing of active HLGAG fragments directly on a chip. We call our process CAN- MS, which stands for Chip Non-covalent Association Mass Spectrometry. Coupling of several methods into one procedure will allow us to study quickly and efficiently HLGAGs with important biological activities and can lend itself to development of a high throughput, automated machine to answer important scientific questions. One specific question that we propose to address is the HLGAG sequence that binds to and promotes the activity of endostatin, a potent endogenous anti-cancer agent. Similar technologies for DNA and proteins include things like gene chips that have revolutionized the study of these molecules. We hope advancements, like out technology, will do the same thing for HLGAGs.