CRYSTALLOGRAPHIC STUDIES OF ANTIBIOTIC RESISTANCE AND SIGNAL TRANSDUCTION

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。 抗生素耐药性的发展对细菌感染是一个严重的威胁，在很大程度上是细菌的内酰胺酶。治疗感染的一种有效的解决方案是联合使用一种内酰胺酶抑制剂（如他唑巴坦、舒巴坦和克拉维酸），不幸的是，这种抑制剂已出现耐药性。我们的建议是集中在描绘在原子水平的抑制剂耐药性的新型内酰胺酶的变种。我们捕获反应中间体的新方法是使用内部拉曼晶体学来预表征抑制剂浸泡的晶体，并确定中间体的类型以及该中间体相对于时间的群体，这导致这种复合物的三种晶体结构（Padayatti等人，JBC 2004 & 2005）。目前的努力集中在SHV β-内酰胺酶的抑制剂抗性变体，与新设计的抑制剂的复合物。需要高和超高分辨率结构来研究预期的细微构象变化以及定位作为反应机制一部分的氢。此外，我们从细菌中结晶了4种不同的环核苷酸结合结构域，它们与离子通道具有显着的同源性。

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 development of antibiotic resistance to bacterial infections is a serious human threats and in large part to bacterial ¿¿¿¿¿¿-lactamases. A powerful solution for treating infections is the co-administration of a ¿¿¿¿¿¿-lactamase inhibitor (such as tazobactam, sulbactam, and clavulanic acid) to which unfortunately resistance has emerged. Our proposal is focused on delineating at an atomic level the inhibitor resistance of the novel ¿¿¿¿¿¿-lactamase variants. Our novel approach to trap reaction intermediates is to use in-house Raman crystallography to pre-characterize the inhibitor soaked crystals and determine the type of intermediate as well as the population of this intermediate with respect to time which resulted in three crystal structures of such complexes (Padayatti et al., JBC 2004 & 2005). Current efforts are to focus on inhibitor resistance variants of SHV beta-lactamase, complexes with novel designed inhibitors. High and ultra-high resolution structures are needed to investigate the subtle conformational changes that are expected as well as locate hydrogens that are part of the reaction mechanism. In addition, we have crystallized 4 different cyclic nucleotide binding domains from bacteria that show a significant homology with that of ion channels.