STRUCTURE FUNCTION RELATIONSHIPS IN POLYSACCHARIDES

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 我们的长期目标是阐明多糖结构及其与溶剂和溶质分子的相互作用，以及在混合多糖系统中的协同相互作用，以获得有关其结构-功能关系的见解。在这方面，目前的建议是关于确定一些生物学上重要的和工业上有用的多糖的分子结构。该研究包括来自藻类（i ota，kappa和lambda角叉菜胶）;细菌（结冷胶类似物和洋葱）;真菌（葡糖醛酸甘露聚糖）;植物（鼠李糖半乳糖醛酸聚糖）;木材（半乳葡甘露聚糖）和二元系统（细菌黄原胶：植物葡甘露聚糖和细菌丙酮：植物葡甘露聚糖）的样品。最近，我们证明了小分子如苯并噻吩和百里酚可以被捕获在结晶的ι-角叉菜胶网络中，导致聚合物共晶（未发表的结果）。因此，我们的第二个目标是集中在聚合物共晶（从几个FDA批准的多糖与小药物分子结合获得）的表征，并确定其三维结构。希望这些结果有助于了解多糖与药物的相互作用，并有助于药物控释载体的开发。 这些多糖或多糖复合物具有形成螺旋结构的固有趋势，其仅具有有限的横向排序，并且不适合于生长单晶。因此，纤维衍射是可视化其三维组织的唯一方法。这些结构信息对于理解它们与溶剂和溶质分子以及与其他多糖的相互作用以使它们在食品和药物应用中有效利用是必不可少的。这些结果将进一步突出多糖在糖胺聚糖和细胞壁中的构象空间。

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such as benzocaine and thymol can be entrapped in crystalline iota-carrageenan network leading to polymeric cocrystals (unpublished results).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.