STRUCTURE FUNCTION RELATIONSHIPS IN POLYSACCHARIDES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 我们的长期目标是阐明多糖的结构及其与溶剂和溶质分子的相互作用，以及混合多糖体系中的协同作用，以获得对其结构-功能关系的深入了解。在这方面，目前的建议是关于确定一些具有生物重要性和工业用途的多糖的分子结构。这项研究包括藻类(IOTA、kappa和lambda carrageenans)、细菌(结冷胶类似物和洋葱)、真菌(葡醛酸木甘露聚糖)、植物(鼠李糖醛酸半乳糖甘露聚糖)、木材(半乳甘露聚糖)和一个二元体系(细菌黄原胶：植物葡甘聚糖和细菌丙烷：植物葡甘露聚糖)的样品。最近，我们证明了像苯佐卡因和百里香酚这样的小分子可以被包裹在结晶的IOTA-卡拉胶网络中，从而形成聚合物共晶体(未发表的结果)。因此，我们的第二个目标集中在聚合物共晶体(从FDA批准的几种多糖与小药物分子结合获得)的表征上，并确定它们的三维结构。希望这些结果有助于理解多糖类药物之间的相互作用，从而发展药物控释载体。 这些多糖或多糖复合体具有形成螺旋结构的固有倾向，仅具有有限的侧向有序性，不适合生长单晶。因此，纤维衍射是可视化其三维结构的唯一方法。这些结构信息对于了解它们与溶剂和溶质分子的相互作用以及与其他多糖的相互作用，以便在食品和医药应用中有效地利用它们是至关重要的。这一结果将进一步突出多糖的构象空间，因为它们存在于糖胺聚糖和细胞壁中。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our long term goals are to elucidate polysaccharide structures and their interactions with solvent and solute molecules as well as the synergistic interactions in mixed polysaccharide systems towards gaining insights about their structure-function relationships. In this regard, the current proposal is about determining the molecular architecture of a number of biologically important and industrially useful polysaccharides. The study includes the samples from algal (iota, kappa and lambda carrageenans); bacterial (gellan analog and cepacian); fungal (glucuronoxylomannan); plant (rhamnogalacturonan); wood (galactoglucomannan) and a binary system (bacterial xanthan:plant glucomannan and bacterial acetan:plant glucomannan). More recently, we demonstrated that small molecules such as benzocaine and thymol can be entrapped in crystalline iota-carrageenan network leading to polymeric cocrystals (unpublished results). Thus, our second aim is centered on the characterization of polymeric cocrystals (obtained from several FDA approved polysaccharides combined with small drug molecules) and determining their three-dimensional structures. It is hoped that these results would be helpful in understanding the polysaccharide:drug interactions towards the development of controlled drug releasing carriers. These polysaccharides or polysaccharide complexes have an inherent tendency to form helical structures with only limited lateral ordering and are not amenable for growing single crystals. Hence, fiber diffraction is the only method of choice for visualizing their three-dimensional organization. Such structural information is essential for understanding their interactions with solvent and solute molecules as well as with other polysaccharides for their effective utilization in food and pharmaceutical applications. The results will further highlight the conformational space available to polysaccharides as they occur in glycosaminoglycans and cellular walls.