SYNTHESIS OF GLYCOSAMINOGLYCAN OLIGOSACCHARIDES

描述：(主要研究人员摘要)糖胺聚糖(GAG)是 一族结构复杂、高度硫酸盐化、多分散、线性的 多糖类。肝素、硫酸肝素、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，最多的 被广泛研究的Gag，是丝氨酸蛋白酶抑制剂等的主要激活剂 最近，肝素和其他GAG已被证明在 细胞生长和细胞间相互作用的调节。近300公吨的 全世界每年都从动物组织中生产肝素，并将其用作 抗凝剂。这种活性源于肝素与抗凝血酶III的结合。 使其成为凝血酶和其他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是化学上的 合成步骤多于60步，小于0.25% 投降。尽管这种合成具有挑战性，但这种五糖仍在使用 在整个欧洲进行治疗。肝素的化学合成还没有 由于它的大尺寸和复杂的结构，人们一直在尝试。曾经有过 有关合成含有其他GAG的低聚糖的报道很少。 摘要首次提出了GaG寡糖的合成方法。 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 具有多种硫化模式的四糖；(2)硫酸乙酰肝素 八糖；(3)结合肝素的四糖和八糖 碱性成纤维细胞生长因子；(4)成纤维细胞生长因子结合肝素的类似物 含有修饰官能团的四糖将用以下方法合成 一种新的硫酸盐印迹方法及其在构效关系中的应用 研究；(5)裂解酶合成杂化糖胺低聚糖 从肝素、硫酸肝素、软骨素衍生的二糖构建块 硫酸盐、皮肤素硫酸盐和透明质酸。它们之间的相互作用 人工合成的寡糖将与一些Gag结合蛋白 已评估。裂解酶将应用于修饰的GAG以制备四糖 这将把这项提议中开发的化学物质扩展到更大的 寡糖靶标。

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.