CRYSTALLOGRAPHIC STUDIES OF ANTIBIOTIC RESISTANCE AND SIGNAL TRANSDUCTION

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。 对细菌感染产生抗药性是对人类的严重威胁，在很大程度上是对细菌内酰胺酶的抗药性。治疗感染的一个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，这种药物已经出现了耐药性。我们的建议侧重于在原子水平上描述新型内酰胺酶变异体的抗药性。我们捕捉反应中间体的新方法是使用内部拉曼结晶学来预先表征被缓蚀剂浸泡的晶体，并确定中间体的类型以及该中间体相对于时间的数量，这导致了此类络合物的三种晶体结构(Padayatti等人，JBC 2004&2005)。目前的努力集中在SHVβ-内酰胺酶的抗药性变体上，即与新设计的抑制剂形成的复合体。需要高分辨率和超高分辨率的结构来研究预期的微妙构象变化，以及定位作为反应机理一部分的氢。此外，我们还从细菌中结晶了4个不同的环核苷酸结合域，它们与离子通道的环核苷酸结合域具有显著的同源性。

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.