Biological Activity of novel glycosaminoglycan and interaction with binding proteins.

我们最近从非洲巨蜗牛Achatina fulica中发现了一种新的糖胺聚糖，并鉴定了这种新的糖胺聚糖是由均相双糖（*4GlcNpAcalpha1*4IdoAp2Salpha）重复单元组成的。该多糖被命名为硫酸阿恰兰，具有独特的硫酸肝素家族序列，具有血管生成活性。本研究检验了硫酸acharan中含有的寡糖序列与细胞外基质中存在的蛋白质中的一致肽序列具有高亲和力的假设。采用部分酶切法制备了硫酸阿恰兰二糖至十四糖等多种不同粒径的低聚糖。利用这些低聚糖分离出高亲和蛋白，并对其组成和序列进行了分析。低聚糖-蛋白相互作用检测：1。结合亲和力（Kd）；2. 结合特异性；3. 结合热力学；4. 更有方向性；和5。绑定站点结构要求！多肽也将被合成，以包含共识序列的变化和修饰寡糖，如n -去乙酰化和再n -磺化硫酸阿卡兰，被合成，以帮助建立寡糖-肽相互作用的结构活性关系。将天然蛋白与合成肽进行比较，以确定结合的特异性。玻璃体连接蛋白和重组酸性成纤维细胞生长因子是值得研究的蛋白，因为它们与硫酸阿恰兰/肝素/硫酸肝素结合具有重要的生物学后果。最终，这些研究将导致定制设计的多肽增加低聚糖结合亲和力，以增强或减弱与低聚糖-蛋白质相互作用相关的活性。这些低聚糖和多肽代表了新药设计的起点，重点是肽模拟物和硫酸低聚糖模拟物。这些新的治疗药物可能用于调节多种生物过程，包括血管生成、转移、动脉粥样硬化、免疫反应、HIV感染和血栓形成。少

We have very recently found a new glycosaminoglycan from African Giant Snail, Achatina fulica, and have characterized that this new glycosaminoglycan is consisting of homogeneous disaccharide (*4GlcNpAcalpha1*4IdoAp2Salpha) repeating unit. This polysaccharide, named acharan sulfate, has a unique sequence belonging in heparan sulfate family and shows angeogenesis activity.This study examined the hypothesis that contain oligosaccharide sequences in acharan sulfate have high affinity for consensus peptide sequences in proteins present in the extracellular matrix. A variety of different size of oligosaccharides in the range from disaccharide to tetradecasaccharide of acharan sulfate were prepared by partial enzymatic digestion. These oligosaccharides were used to isolate high affinity proteins, which were examined for composition and sequence. Oligosaccharide-protein interactions were examined for : 1. binding affinity (Kd) ; 2. binding specificity ; 3. Binding thermodynamics ; 4. binding … More orientation ; and 5. binding site structural requirements! Peptides will also be synthesized to contain variations of the consensus sequence and modified oligosaccharides such as N-de-acetylated and re-N-sulfonated acharan sulfate, were synthesized to help establish the structure activity relationship for oligosaccharide-peptide interaction. Native protein will be compared with synthetic peptide to confirm specificity of binding. Vitronectin and recombinant acidic fibroblast growth factor are the proteins to be studied because of the important biological consequences of their binding to acharan sulfate/heparin/heparan sulfate. Ultimately, these studies should lead to custom designed peptides that have increased oligosaccharide binding affinity to enhance or attenuate the activities associated with oligosaccharide-protein interaction. These oligosaccharides and peptides represent the starting point for new drug design focused on peptido-mimetics and sulfated oligosaccharide-mimetics. Such new therapeutic agents might be used to regulate a variety of biological processes including angiogenesis, metastasis, atherogenesis, immune responses, HIV infection, and thrombosis. Less