STRUCTURE FUNCTION RELATIONSHIPS IN POLYSACCHARIDES

这个子项目是许多研究子项目中的一个 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来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们的长期目标是阐明（非结晶）生物聚合物，特别是多糖的分子结构，以及它们与溶剂和溶质分子的相互作用，以及混合多糖中的协同相互作用，以深入了解它们的功能行为。在这方面，本建议的主要推力集中在确定一系列生物学上重要的和工业上有用的多糖的三维结构。在本研究中，我们正在进行的研究将包括但不限于（如有需要）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）的标本。 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对于它们在食品和药物应用中的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。 聚合物水溶液经室温拉伸可得到取向的多晶纤维。利用连接原子最小二乘法（LALS）程序建立符合衍射图样的分子模型并求解结构。

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 the molecular structures of (non-crystalline) biopolymers, especially polysaccharides, and their interactions with solvent and solute molecules and the synergistic interactions in mixed polysaccharides towards an in depth understanding of their functional behavior. In this regard, the main thrust of the present proposal is centered on determining the three-dimensional structures of a series of biologically important and industrially useful polysaccharides. In this reagard, our ongoing study will include, but not limited to (as need arises), the specimens 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). 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 towards 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. Oriented and polycrystalline fibers will be obtained from aqueous polymer solutions through stretching process at room temperature. Linked-Atom Least-Squares (LALS) program will be used to build the molecular models to be in conformity with the diffraction pattern and to solve the structure.