SAXS STUDIES OF THE BACTERIAL CELL WALL

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。 细胞壁是细菌细胞的基本结构。这种千兆吨大小的大分子网络包裹了整个细胞，并保护细菌免受机械应力的影响。事实上，干扰细胞壁合成或周转的抗生素会导致细胞溶解，这是由于高浓度的（约100毫克）。3个大气压）内部渗透压几十年前，细菌细胞壁通过小角度溶液X射线散射进行了检查，但使用的光源（旋转阳极）亮度低得多，并且处于脱水状态。这些实验表明，细菌细胞壁是非周期性的。 然而，新的数据表明，它们是周期性的。我们正试图通过电子冷冻断层扫描技术来解决这个问题，但希望用SAXS来补充这些研究。 我们相信，强大的现代同步加速器可能会揭示比以前获得的更多关于短程有序的细节，这将区分和完善现有的细胞壁结构模型。

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. The cell wall is a fundamental structure of the bacterial cell. This Gigadalton-sized macromolecular meshwork encases the entire cell and protects bacteria from mechanical stress. Indeed, antibiotics that interfere with cell wall synthesis or turnover cause the cell to lyse due to the high (ca. 3 atm.) internal osmotic pressure. Bacterial cell walls were examined by small angle solution x-ray scattering a few decades ago, but with much less bright sources (rotating anodes), and in a dehydrated state. These experiments suggested that bacterial cell walls are non-periodic. New data, however, suggest they are periodic. We are in the midst of trying to resolve the question by electron cryotomographic techniques, but wish to complement these studies with SAXS. We believe the powerful modern synchrotrons may reveal significantly more detail about short-range order than was obtained earlier, which would differentiate and refine the existing models of cell wall structure.