SYNTHESIS OF GLYCOSAMINOGLYCAN OLIGOSACCHARIDES

描述：（主要研究者摘要）糖胺聚糖（GAG）是 结构复杂、高度硫酸化、多分散、线性的 多糖肝素、硫酸乙酰肝素、硫酸软骨素、皮肤素 硫酸盐和透明质酸都是这个家族的成员。肝素，最 广泛研究的GAG是丝氨酸蛋白酶抑制剂的主要激活剂， 最近，肝素和其他GAG已被证明在 调节细胞生长和细胞与细胞相互作用。近300公吨的 肝素每年在世界范围内从动物组织中生产， 抗凝剂这种活性是由于肝素与抗凝血酶III结合而产生的 使其成为凝血酶和其它重要丝氨酸蛋白酶的有效抑制剂。 与抗凝血酶结合的五糖序列，已被化学地 在超过60个合成步骤中合成， 产率尽管这一具有挑战性的合成，这种五糖被用于 在整个欧洲治疗。肝素的化学合成没有 由于其体积大，结构复杂，一直在进行尝试。有 很少有报道合成包含其它GAG的寡糖。 提出了GAG寡糖的合成方法，其中GAG是第一个 使用多糖裂解酶解聚成二糖。五个目标 已选择用于合成的结构：（1）硫酸乙酰肝素 具有多种硫酸化模式的四糖;（2）硫酸乙酰肝素 八糖;（3）肝素四糖和八糖， 碱性成纤维细胞生长因子（FGF）;（4）FGF结合肝素的类似物 含有修饰的官能团的四糖将使用 一种新的硫酸根印迹方法及其在构效关系研究中的应用 研究;（5）使用裂解酶合成的杂合糖胺聚糖寡糖 从肝素、硫酸乙酰肝素、软骨素衍生的二糖结构单元 硫酸盐、硫酸皮肤素和透明质酸。这些因素的相互作用 将合成寡糖与许多GAG结合蛋白结合， 评估。将裂解酶应用于修饰的GAG以制备四糖 这将使该提案中开发的化学物质扩展到更大的 寡糖靶点。

DESCRIPTION: (Principal Investigator's Abstract) Glycosaminoglycans (GAGs) are a family of structurally complex, highly sulfated, polydisperse, linear polysaccharides. Heparin, heparan sulfate, chondroitin sulfates, dermatan sulfate, and hyaluronic acid are all members of this family. Heparin, the most widely studied GAG, is a major activator of serine protease inhibitors and more recently heparin and other GAGs have been shown to be important in the regulation of cell growth and cell-cell interaction. Nearly 300 metric tons of heparin are produced worldwide each year from animal tissue and used as an anticoagulant. This activity results from heparin binding to antithrombin III making it a potent inhibitor of thrombin and other important serine proteases. The pentasaccharide sequence binding to antithrombin, has been chemically synthesized in greater than 60 synthetic steps and in less than 0.25 percent yield. Despite this challenging synthesis, this pentasaccharide is being used therapeutically throughout Europe. The chemical synthesis of heparin has not been attempted because of its large size and complex structure. There have been few reports of the synthesis of the oligosaccharide comprising the other GAGs. The synthesis of GAG oligosaccharides is proposed in which the GAG is first depolymerized into disaccharides using polysaccharide lyases. Five target structures have been chosen for synthesis: (1) a heparan sulfate tetrasaccharide with a variety of sulfation patterns; (2) a heparan sulfate octasaccharide; (3) the heparin tetrasaccharide and octasaccharide that bind basic fibroblast growth factor (FGF); (4) analogs of the FGF binding heparin tetrasaccharide containing modified functional groups will be synthesized using a novel sulfate imprinting method and used in structure activity relationship studies; (5) hybrid glycosaminoglycan oligosaccharides synthesized using lyase derived disaccharide building blocks from heparin, heparan sulfate, chondroitin sulfate, dermatan sulfate and hyaluronic acid. The interaction of these synthetic oligosaccharides to a number of GAG-binding proteins will be evaluated. Lyases will be applied to modified GAGs to prepare tetrasaccharides that will extend the chemistry developed in this proposal to larger oligosaccharide targets.