Biological Activity of novel glycosaminoglycan and interaction with binding proteins.

我们最近从非洲大蜗牛Achatinafulica中发现了一种新的糖胺聚糖，并确定了这种新的糖胺聚糖由均一的二糖（* 4GlcNpAcalpha 1 * 4 IdoAp 2Salpha）重复单元组成。硫酸乙酰肝素（heparan sulfate）是硫酸乙酰肝素（heparan sulfate）家族中的一种具有血管生成活性的多糖，本研究验证了硫酸乙酰肝素（heparan sulfate）中含有的寡糖序列对细胞外基质中蛋白质的共有肽序列具有高亲和力的假设。采用部分酶解法制备了从硫酸阿查兰二糖到十四糖的各种不同大小的寡糖。这些寡糖用于分离高亲和力蛋白质，检查其组成和序列。寡糖-蛋白质相互作用进行了检查：1。结合亲和力（Kd）; 2.结合特异性; 3.结合热力学; 4.结合 ...更多信息 方向;和5.装订部位结构要求！还将合成肽以包含共有序列的变体，并且合成修饰的寡糖如N-脱乙酰化和重新-N-磺化的阿查兰硫酸酯，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，以确认结合特异性。玻连蛋白和重组酸性成纤维细胞生长因子是要研究的蛋白质，因为它们与硫酸乙酰肝素/肝素/硫酸乙酰肝素结合的重要生物学后果。最终，这些研究应导致定制设计的肽，其具有增加的寡糖结合亲和力以增强或减弱与寡糖-蛋白质相互作用相关的活性。这些寡糖和肽代表了新药物设计的起点，重点是肽模拟物和硫酸化寡糖模拟物。这些新的治疗剂可能用于调节多种生物学过程，包括血管生成、转移、动脉粥样硬化形成、免疫应答、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