Systematic Design of Histone-Derived Antimicrobial Peptides

项目摘要 对常规抗生素产生耐药性的细菌是日益严重的公共卫生问题。 抗微生物肽（AMP）是一种潜在的替代方案，可以对抗这些问题。 细菌一个有趣的AMP家族是组蛋白衍生的抗菌肽（HDAP）。 HDAP已经从天然来源中分离出来，并且许多这些肽的机制 已经通过实验确定。然而，相对较少的重点已经给予了 合理优化和设计HDAP以工程化更有活性的肽。这项建议旨在 为了解决这一差距，通过有目的和设计动机的调查，另外三个 我们假设会影响HDAP活性的因素：肽截短，杂合物的形成， 肽，和抗生素+AMP鸡尾酒的联合治疗。 我们采用了一组精心挑选的四个代表性的HDAP，BF 2和三个设计 肽DesHDAP 1、DesHDAP 2和DesHDAP 3A。这些肽被选择来跨越两个 AMP与细胞膜相互作用的广泛类别-跨膜转运的肽 质膜（BF 2和DesHDAP 1）和那些诱导显著的膜 透化（DesHDAP 2和DesHDAP 3A）。这些肽还反映了一系列初始的 抗菌活性因此，我们认为他们提供了一个易于处理的样本量， 提供足够的分子多样性以确定趋势。我们的方法包括结合 细菌和真核细胞分析，共聚焦显微镜，光谱测量，和 分子动力学模拟。 在阐明了我们提出的影响HDAP活性的三个因素的趋势之后，我们 我们将联合收割机结合这些信息，创造一个新的系列， 通过基于文库的方法从组蛋白序列中鉴定的肽， 肽活性的单个因素。因此，我们可以评估我们的趋势的普遍性， 验证这是否是HDAP中肽设计的有用方法。 这些研究将促进HDAP作为潜在治疗剂的发展， 提供对HDAP结构-功能关系的深入了解，这些关系可能会扩展到 其他AMP家族除了这些科学目标之外，这项研究还非常强调 由于这项工作将由几名本科生研究人员和一些最近的 韦尔斯利学院是一所只招收本科生的女子学院。

Project Summary Bacteria that have developed resistance to conventional antibiotics are an increasing public health concern, and antimicrobial peptides (AMPs) represent a potential alternative to combat these bacteria. One intriguing family of AMPs is the histone-derived antimicrobial peptides (HDAPs). HDAPs have been isolated from natural sources, and the mechanisms for many of these peptides have been determined experimentally. However, relatively little focus has been given to the rational optimization and design of HDAPs to engineer more active peptides. This proposal aims to address this gap through purposeful and design-motivated investigations of three additional factors that we hypothesize will impact HDAP activity: peptide truncations, the formation of hybrid peptides, and combination therapy with antibiotic+AMP cocktails. We are employing a carefully selected set of four representative HDAPs, BF2 and three designed peptides DesHDAP1, DesHDAP2 and DesHDAP3A. These peptides were chosen to span the two broad categories for AMP interaction with cell membranes—peptides that translocate across plasma membranes (BF2 and DesHDAP1) and those that induce significant membrane permeabilization (DesHDAP2 and DesHDAP3A). These peptides also reflect a range of initial antibacterial activities. Thus, we feel that they provide a tractable sample size that nonetheless provide sufficient molecular diversity to identify trends. Our methods include a combination of bacterial and eukaryotic assays, confocal microscopy, spectroscopic measurements, and molecular dynamics simulations. After elucidating trends for our three proposed factors that affect HDAP activity with our representative set of four peptides, we will combine this information to create a novel series of peptides identified from histone sequences through a library-based approach that optimizes the individual factors for peptide activity. We can thus assess the generalizability of our trends to validate whether this is a useful approach for peptide design in HDAPs. These studies will promote the development of HDAPs as potential therapeutic agents and provide insights into HDAP structure-function relationships that potentially can be expanded to other AMP families. In addition to these scientific goals, this research also has a strong emphasis on training as the work will be carried out by several undergraduate researchers and a few recent graduates at Wellesley College, an undergraduate-only women’s college.