Systematic Design of Histone-Derived Antimicrobial Peptides

项目摘要 对常规抗生素产生抗药性的细菌正在日益增加的公共健康 关注，和抗菌肽(AMP)是一种潜在的替代方案来对抗这些 细菌。一个耐人寻味的AMP家族是组蛋白衍生的抗菌肽(HDAP)。 HDAP已从天然来源中分离出来，其中许多多肽的作用机制 都是通过实验确定的。然而，相对较少的关注集中在 合理优化和设计HDAP，以设计出更具活性的多肽。这项提议旨在 通过有目的和有设计动机的另外三项调查来解决这一差距 我们假设会影响HDAP活性的因素：肽的截短、杂交体的形成 多肽，以及与抗生素AMP鸡尾酒的联合治疗。 我们正在使用一套精心挑选的四个具有代表性的HDAP，BF2和三个设计 DesHDAP1、DesHDAP2和DesHDAP3A。这些多肽被选择来跨越这两个 AMP与细胞膜相互作用的广泛类别--跨膜转运的多肽 质膜(BF2和DesHDAP1)和那些诱导显著膜的 渗透性(DesHDAP2和DesHDAP3A)。这些多肽还反映了一系列初始的 抗菌活性。因此，我们认为它们提供了一个易于处理的样本量，但 提供足够的分子多样性，以确定趋势。我们的方法包括组合 细菌和真核生物分析、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活动的三个因素的趋势后，我们 四个具有代表性的多肽，我们将结合这些信息来创建一系列新颖的 通过基于文库的方法从组蛋白序列中鉴定出的多肽 影响多肽活性的个体因素。因此，我们可以评估我们的趋势的概括性 验证这是否是HDAP中肽设计的有用方法。 这些研究将促进HDAP作为潜在的治疗剂和 提供对HDAP结构-功能关系的洞察，这些关系可能会扩展到 其他AMP家族。除了这些科学目标外，这项研究也有很强的侧重点 关于培训，因为这项工作将由几名本科生研究人员和最近几名 卫尔斯理学院的毕业生，这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.