STRUCTURAL STUDIES ON THE ROLE OF ZINC IN BACTERIAL PROLIFERATION

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。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。所列机构为中心，不一定是研究者所在机构。最成功的抗生素作为机制为基础的抑制剂的特定细胞过程涉及细菌的增殖和毒力。VanX（万古霉素耐药性）和金属-？-对单个细菌起防御作用的内酰胺酶（青霉素抗性）和在细胞间细菌通讯（群体淬灭）中起显著作用的AHL-内酯酶的控制毒力的过程中。这些系统的共同点是它们依赖于Zn（II）的活性，以及它们在活性位点结合钴作为高自旋（hs）Co（II）离子的能力。每一个都代表了一个重要的临床目标。我们已经使用X-射线吸收光谱（XAS）和多频电子顺磁共振（EPR）来研究上述酶在其静息状态下的天然Zn和Co取代形式。我们最近开始研究催化相关的中间体使用快速冷冻淬火技术。更详细的磁共振实验将探测更微妙的结构细节，以建立催化作用的结构时间轴。

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 most successful antibiotics act as mechanism-based inhibitors of specific cellular processes involved in bacterial proliferation and virulence. Mechanistic investigations of VanX (vancomycin resistance) and the metallo-?-lactamases (penicillin resistance), which play defensive roles for an individual bacterium, and of the AHL-lactonase, which plays a prominent role in intercellular bacterial communication (quorum quenching), controlling virulence, are in process. The common thread to these systems is their dependence on Zn(II) for activty, and their ability to bind cobalt at the active site as the high-spin (hs) Co(II) ion. Each represents an important clinical target. We have used x-ray absorption spectroscopy (XAS) and multi-frequency electron paramagnetic resonance (EPR) to study both the native Zn and Co-substituted forms of the aforementioned enzymes in their resting states. We have recently begun to study catalytically relevant intermediates using rapid-freeze-quench techniques. More detailed magnetic resonance experiments will probe more subtle structural details, in order to establish a structural timeline for catalysis.