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

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）：传染病仍然是全世界死亡的主要原因。这个问题的一个重要方面是对大多数（如果不是全部）传统抗生素具有耐药性的感染持续增加。为了应对这一挑战，必须确定新的药物靶点并开发新类别的抗生素。在过去的二十年中，在脊椎动物和无脊椎动物物种中发现了大量天然存在的抗菌肽，它们能够对多种病原体产生快速和广谱的反应。由于这些肽的特异性是基于对细胞膜一般特性的认识，因此耐药性的出现极其罕见，这使得它们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对其作用机制的详细了解，特别是它们与细胞膜相互作用和破坏细胞膜的方式。该提案的目标是清楚地了解肽-膜相互作用和一类有前途且明确的抗菌肽的作用机制，这些抗菌肽是昆虫肽天蚕素 A 和蜂毒肽蜂毒肽的合成混合物。定点自旋标记 (SDSL) 电子顺磁共振 (EPR) 光谱为分析肽-膜相互作用提供了一种强大且完善的方法，特别适合提供如此详细的理解。具体来说，我们将使用传统和脉冲 SDSL EPR 来测量膜结合亲和力，确定模拟真核和细菌膜的模型膜中的天蚕素-蜂毒肽混合肽的结构、拓扑、膜插入程度以及肽-肽相互作用。完整的细胞。这些特性将与抗生素针对一组药物敏感和耐药细菌的功效相关。我们将系统地修改肽组成，以确定序列、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-氨基酸组成的拟肽类似物的抗生素功效和膜相互作用。这些研究将显着增进我们对抗菌肽作用机制的理解，并有助于肽和拟肽抗生素的进一步开发。