Spin-Labeled Peptide Antibiotics

自旋标记肽抗生素

• 批准号: 6952322
• 负责人: Jimmy Feix
• 金额: $ 24.92万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-30 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6952322
• 关键词: antibiotics; biotherapeutic agent; cell membrane; chemical binding; chimeric proteins; drug screening /evaluation; electron spin resonance spectroscopy; lipid bilayer membrane; liposomes; melittin; membrane channels; peptide analog; peptide chemical synthesis; peptide structure; pharmacokinetics; pore forming protein; protein structure function; antibiotics; biotherapeutic agent; cell membrane; chemical binding; chimeric proteins; drug screening /evaluation; electron spin resonance spectroscopy; lipid bilayer membrane; liposomes; melittin; membrane channels; peptide analog; peptide chemical synthesis; peptide structure; pharmacokinetics; pore forming protein; protein structure function

DESCRIPTION (provided by applicant): Infectious disease remains the leading cause of mortality worldwide. A significant aspect of this problem is the continuing rise of infections that are resistant to most, if not all, conventional antibiotics. To meet this challenge it is essential that new drug targets be identified, and new classes of antibiotics developed. Over the past two decades a large number of naturally-occurring antimicrobial peptides have been found in both vertebrate and invertebrate species that are capable of providing a rapid and broad-spectrum response against a wide variety of pathogens. Because the specificity of these peptides is based on recognition of general properties of the cell membrane the emergence of resistance is exceedingly rare, making them ideal starting points for the development of new antibiotics. A limiting factor in our ability to further enhance the efficacy of these peptides is the lack of detailed knowledge about their mechanism of action, and in particular the manner in which they interact with and disrupt the cell membrane. The goal of this proposal is to develop a clear understanding of peptide-membrane interactions and mechanism of action for a promising and well-defined class of antimicrobial peptides that are synthetic hybrids of the insect peptide cecropin A and the bee-venom peptide, mellitin. Site-directed spin labeling (SDSL) electron paramagnetic resonance (EPR) spectroscopy provides a powerful and well-established approach for the analysis of peptide-membrane interactions that is uniquely suited to providing such a detailed understanding. Specifically, we will use both conventional and pulsed SDSL EPR to measure membrane binding affinities, determine structure, topology, degree of membrane insertion, and peptide-peptide interactions for cecropin-mellitin hybrid peptides in model membranes that mimic both eukaryotic and bacterial membranes and in intact cells. These properties will be related to antibiotic efficacy against a panel of drug-sensitive and drug-resistant bacteria. We will systematically modify peptide composition to define relationships between sequence, membrane interactions, and antibacterial efficacy. Finally, we will synthesize and evaluate the antibiotic efficacy and membrane interactions of peptidomimetic analogs composed of non-natural beta-amino acids. These studies will significantly advance our understanding of the mechanism of action of antimicrobial peptides, and contribute to the further development of peptide and peptidomimetic antibiotics.

描述（由申请人提供）：传染病仍然是全球死亡率的主要原因。该问题的一个重要方面是感染的持续增长，这些感染对大多数（如果不是全部）常规抗生素具有抗性。为了应对这一挑战，必须确定新的药物靶标，并开发出新的抗生素。在过去的二十年中，在脊椎动物和无脊椎动物物种中都发现了大量自然抗菌肽，这些肽能够为各种病原体提供快速和广谱的反应。由于这些肽的特异性是基于对细胞膜一般特性的识别，因此抗性的出现极为罕见，因此成为开发新抗生素的理想起点。我们进一步增强这些肽功效的能力的一个限制因素是缺乏有关其作用机理的详细知识，尤其是它们与细胞膜相互作用和破坏细胞膜的方式。该提案的目的是对肽 - 膜相互作用和作用机理进行清晰的了解，以提供有前途且定义明确的抗菌肽类别，这些抗菌肽是昆虫肽葡萄球菌A的合成杂种和蜜蜂 - 粘毒素肽肽，Mellitin，Mellitin。位置定向的自旋标记（SDSL）电子顺磁共振（EPR）光谱学为分析肽 - 膜相互作用的分析提供了一种强大而完善的方法，该方法非常适合提供这种详细的理解。具体而言，我们将同时使用常规和脉冲SDSL EPR来测量膜结合亲和力，确定结构，拓扑，膜插入程度和肽肽相互作用以及模型膜上模仿真菌性膜和细菌膜细胞的模型膜中的cecropin-Mellitin杂交肽以及完整细胞中的结构。这些特性将与对药物敏感和耐药细菌的抗生素功效有关。我们将系统地修改肽组成，以定义序列，膜相互作用和抗菌功效之间的关系。最后，我们将合成并评估由非天然β-氨基酸组成的肽类似物的抗生素功效和膜相互作用。这些研究将大大提高我们对抗菌肽作用机理的理解，并有助于进一步发展肽和肽型抗生素。