Nuclear Magnetic Resonance (NMR) studies of antimicrobial peptides in intact cells

抗菌肽（AMPs）是目前备受关注的课题，部分原因是它们在我们的免疫系统中发挥着重要作用，部分原因是它们有潜力成为对抗日益严重的微生物对传统抗生素耐药性问题的新疗法。然而，我们对这些分子如何工作的理解以及我们利用它们作为更好治疗基础的能力都存在差距。一个这样的差距是由于AMPs的详细机制只在高度简化的系统中进行了研究，这些系统充其量只能近似于AMPs作用的更复杂的细胞包膜。微生物细胞包膜包含许多额外的成分，这些成分可能会影响抗菌肽的工作方式，并可能有助于抗菌肽在不伤害我们自身细胞的情况下杀死微生物。我们打算通过开发高分辨率的定量技术，如核磁共振（NMR）来研究完整细菌和哺乳动物细胞中的amp，从而弥补这一差距。然后，我们将我们的结果与模型系统中的结果进行比较，以更好地了解真实细胞中存在的复杂性如何改变AMP的作用。我们还将从鳕鱼中鉴定和表征新的amp。鳕鱼基因组代表了潜在的新的和有趣的抗菌肽基序的极好来源，因为鳕鱼有一个不发达的适应性免疫系统，但实际上是在病原体的海洋中游泳，所以可能需要特别有效的抗菌肽。这项工作的预期意义包括：在阐明amp机制的核磁共振研究与实际观察活性的条件之间提供急需的联系；开发新的方法，使核磁共振的应用，以研究任何膜蛋白在整个细胞的背景下；通过鉴定和表征新的海洋AMP，为AMP社区以及参与鳕鱼和其他鱼类养殖计划的人提供有意义的信息。

Antimicrobial peptides (AMPs) are currently the subject of significant interest, in part due to their important role in our immune systems and in part due to their potential as novel therapeutics to combat the increasingly serious problem of microbial resistance to conventional antibiotics. However, there are gaps in both our understanding of how these molecules work and in our ability to use them as the basis for better treatments. One such gap results from the fact that the detailed mechanism of AMPs has only been studied in highly simplified systems that only approximate, at best, the much more complex cell envelopes against which the AMPs act. Microbe cell envelopes contain a number of additional components that likely affect how AMPs work and probably contribute to the ability of AMPs to kill microbes at levels that don't harm our own cells. We intend to bridge this gap by developing ways to use high resolution, quantitative techniques, like nuclear magnetic resonance (NMR), to investigate AMPs in whole, intact bacteria and mammalian cells. We will then compare our results to the results in the model systems to better understand how AMP actions are modified by the complexity present in real cells. We will also identify and characterize novel AMPs from cod. The cod genome represents an excellent source of potentially new and interesting antimicrobial peptide motifs, since cod have an underdeveloped adaptive immune system, but are literally swimming in a sea of pathogens and so presumably require especially efficacious AMPs. The anticipated significance of the work includes: supplying a badly needed connection between NMR studies that shed light on the mechanism of AMPs and those conditions under which activity is actually observed; developing new methods that enable the application of NMR to the study of any membrane protein in the context of whole cells; making available information of significance to the AMP community and those involved in cod and other fish breeding programs by identifying and characterizing novel marine AMPs.