Characterization and Design of Histone-Derived Antimicrobial Peptides

描述（由申请人提供）：抗菌肽代表了传统抗生素的潜在替代品，特别是针对已产生耐药性的细菌。虽然以前的几项研究已经注意到组蛋白衍生的抗菌肽（HDAP）的抗菌特性，这些肽的结构-功能关系通常没有得到很好的理解。最具特征的HDAP，buforin II（BF 2），是一种有趣的肽，可以易位到细胞中，在那里它被认为是结合核酸。BF 2进入细胞的能力也使其具有药物递送应用的潜在效用。尽管有关于BF 2的这些知识，但尚不清楚其他HDAP是否具有其膜特性。这项研究将涉及三个具体目标，调查HDAP功能。首先，将使用一系列肽变体研究脯氨酸在BF 2的易位和细菌选择性中的作用。由于脯氨酸残基是常见的抗菌肽，包括其他HDAP，这些研究将提供一般的见解脯氨酸在膜活性肽中发挥的作用。将使用脂质囊泡实验、细胞测定和分子动力学模拟的组合来表征变体的易位和膜相互作用。这些变体也将用于研究脯氨酸残基如何促进BF 2优先靶向细菌而不是真核细胞。其次，将进行一系列实验以确定其他已知的HDAP，包括parasin和hipposin，是否与BF 2共享膜特性。为此，这一目标将使用囊泡研究和细胞测定来测量膜透性和易位的肽含有不同的组合parasin，BF 2，和hipposin域。最后，基于组蛋白晶体结构和BF 2的已知特性，设计了一组三种新型HDAP。在第三个目标中，这些新型HDAP的膜特性将使用在提案的其他部分中应用的实验和计算方法来评估，以表征BF 2和其他已知的HDAP。总的来说，这些研究将提供深入了解HDAP家族中共有的膜特性。此外，这些信息将作为基础，使用组蛋白作为框架，设计新的抗菌和细胞穿透肽所需的性能。 公共卫生相关性：抗菌肽是由多种生物体产生的小蛋白质，代表了对抗对常规抗生素具有抗性的细菌的潜在替代品。这项拟议的研究将提供关于一个特别有趣的抗菌肽家族，组蛋白衍生的抗菌肽，功能的详细信息。提高我们对这些肽的理解将有助于研究人员开发用于治疗用途的新型肽。

DESCRIPTION (provided by applicant): Antimicrobial peptides represent a potential alternative to conventional antibiotics, particularly against bacteria that have developed drug resistance. Although several previous studies have noted the antimicrobial properties of histone-derived antimicrobial peptides (HDAP), the structure-function relationships of these peptides are generally not well understood. The best characterized HDAP, buforin II (BF2), is an intriguing peptide that can translocate into cells, where it is thought to bind nucleic acids. The ability of BF2 to enter cells also gives it potential utility for drug delivery applications. Despite this knowledge about BF2, it is unknown whether other HDAPs share its membrane properties. This proposed research will involve three specific aims investigating HDAP function. First, the role of proline in the translocation and bacterial selectivity of BF2 will be investigated using a series of peptide variants. Since proline residues are common in antimicrobial peptides, including other HDAPs, these studies will provide general insights into the role played by proline in membrane-active peptides. The translocation and membrane interactions of variants will be characterized using a combination of lipid vesicle experiments, cellular assays and molecular dynamics simulations. These variants will also be used to investigate how proline residues promote BF2 preferentially targeting bacteria over eukaryotic cells. Second, a series of experiments will be performed to determine whether other known HDAPs, including parasin and hipposin, share membrane properties with BF2. To this end, this aim will use vesicle studies and cellular assays to measure the membrane permeabilization and translocation of peptides containing different combinations of parasin, BF2, and hipposin domains. Finally, a set of three novel HDAPs has been designed based on histone crystal structures and known characteristics of BF2. In the third aim, the membrane properties of these novel HDAPs will be evaluated using the experimental and computational methods applied in other parts of the proposal to characterize BF2 and other known HDAPs. Overall, these studies will provide insights into what membrane properties are shared within the HDAP family. Moreover, this information will serve as a foundation for using histones as a framework for designing novel antimicrobial and cell-penetrating peptides with desired properties. PUBLIC HEALTH RELEVANCE: Antimicrobial peptides, which are small proteins produced by a wide variety of organisms, represent a potential alternative to combat bacteria that are resistant to conventional antibiotics. This proposed research will provide detailed information about how a particularly intriguing family of antimicrobial peptides, the histone-derived antimicrobial peptides, functions. Improving our understanding of these peptides will help researchers develop novel peptides for therapeutic use.