Design of New Antimicrobials

新型抗菌药物的设计

• 批准号: 8075013
• 负责人: ROBERT S HODGES
• 金额: $ 36.09万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8075013
• 关键词: Address; Adopted; Amino Acid Substitution; Amino Acids; Animal Model; Antibiotic Resistance; Antibiotics; Antimicrobial Cationic Peptides; Bacteria; Bacterial Infections; Benign; Biological; Biological Models; Bioterrorism; Cell Wall; Cell membrane; Cells; Charge; Clinic; Clinical; Coupled; Cytolysis; Development; Dimerization; Economics; Engineering; Ensure; Environment; Enzymes; Eukaryotic Cell; Face; Goals; Health; Hospitalization; Human; Human Cell Line; Hydrophobic Interactions; Hydrophobic Surfaces; Hydrophobicity; Incentives; Infection; Knowledge; Laboratories; Lead; Lipids; Location; Lytic; Marketing; Measurable; Measures; Membrane; Nature; Normal Cell; Nosocomial Infections; Penetration; Peptides; Prokaryotic Cells; Proteolysis; Pseudomonas aeruginosa; Resistance; Resistance development; Safety; Series; Side; Solutions; Specificity; Structure; Surface; Testing; Therapeutic; Therapeutic Index; Toxic effect; Tuberculosis; Vancomycin resistant enterococcus; Variant; aggressive therapy; antimicrobial; antimicrobial peptide; aqueous; bacterial resistance; cellular targeting; cost; design; improved; in vivo; interest; killings; microbial; microorganism; novel; pathogen; prevent; public health relevance; receptor; solid state nuclear magnetic resonance; success

DESCRIPTION (provided by applicant): The dramatic and ever-increasing emergence of many relevant strains of bacteria resistant to traditional antibiotics is now a major issue in human health. Antibiotic resistance has arisen due to the extensive clinical use of classical antibiotics. Thus, at best, antibiotics are progressively demonstrating decreased efficacy; at worst, there has been an upsurge of untreatable infections, such as multi-resistant tuberculosis and vancomycin-resistant Enterococcus strains. Consequently, the cost of treating nosocomial infections through extended hospitalization and increasingly aggressive therapy has risen to an estimated $30 billion in the U.S. Therefore, there is an economic incentive to adopt novel antibiotics. In addition, the threat of bioterrorism, that is the ability to easily engineer new strains of bacteria with deadly consequences to humans, must be dealt with. Compared to existing antibiotics, antimicrobial peptides show great potential as a radically new structural class of antibiotics, with both novel modes of action as well as different cellular targets. The development of resistance to membrane active peptides whose sole target is the cytoplasmic membrane is not expected since this would require substantial changes in the lipid composition of cell membranes of microorganisms. The advantages of cationic antimicrobial peptides are their ability to kill target cells rapidly, their unusual broad spectrum activity and their activity against some of the more serious antibiotic-resistant pathogens isolated in clinics. The major barrier to the use of antimicrobial peptides as antibiotics has been their toxicity or ability to lyse eukaryotic cells. We have taken an approach of systematic alteration in the amphipathicity, hydrophobicity and structure of two different classes of antimicrobial peptides by single L- and D- amino acid substitutions. With this approach we were able to dissociate anti-eukaryotic activity from antimicrobial activity, i.e. increase the antimicrobial activity and dramatically reduce or eliminate toxicity to normal cells (as measured by hemolytic activity). We have discovered lead compounds in two different structural classes of antimicrobial peptides, a 14-residue cyclic 2-sheet peptide and a 26-residue 1-helical peptide with clinical potential as broad spectrum antibiotics. The simultaneous development of both classes of compounds will most rapidly advance our knowledge of the mechanism of action of these peptides and the common requirements for selectivity for microbial membranes. Further optimization of our de novo designed lead compounds is required to ensure we obtain the best antimicrobial activity while maintaining a high therapeutic index. Key goals: 1) to determine the best type of positively-charged residue in the center of the non-polar face to enhance specificity on the cyclic 2- sheet and 1-helical peptides; 2) having selected the best positively-charged residue to eliminate hemolytic activity, can we increase hydrophobicity to improve antimicrobial activity while maintaining a high therapeutic index; 3) to demonstrate that our peptides are non-toxic to a series of human cell lines; 4) to show by structural determination (solid-state NMR) the location of our two classes of antimicrobial peptides in the membrane; 5) to demonstrate in vivo efficacy of our peptides against Pseudomonas aeruginosa challenge in two animal models; 6) to extend our studies to animal models of other serious bacterial infections. PUBLIC HEALTH RELEVANCE: The dramatic and ever-increasing emergence of many relevant strains of bacteria resistant to traditional antibiotics is now a major issue in human health. Antibiotic resistance has arisen due to the extensive clinical use of classical antibiotics. Consequently, the cost of treating nosocomial infections through extended hospitalization and increasingly aggressive therapy has risen to an estimated $30 billion in the U.S. Thus, there is an economic incentive to adopt novel antibiotics.

描述（由申请人提供）：许多相关菌株对传统抗生素具有抗药性的相关菌株的戏剧性和不断增长的出现现在是人类健康中的一个主要问题。由于经典抗生素的广泛使用，抗生素耐药性已引起。因此，充其量，抗生素正在逐渐证明疗效降低。最糟糕的是，人们一直在不可治疗的感染，例如多耐肺结核和抗性霉素的肠球菌菌株。因此，通过扩大住院和越来越积极的治疗来治疗医院感染的成本已上涨至美国约300亿美元，因此，有一种经济动力来采用新颖的抗生素。此外，必须处理生物恐怖主义的威胁，即必须处理对人类带来致命后果的新细菌菌株的能力。与现有的抗生素相比，抗菌肽作为一种巨大的新结构抗生素类别具有巨大的潜力，具有新型的作用方式和不同的细胞靶标。不期望其唯一靶靶的膜活性肽的耐药性的发展，因为这将需要微生物细胞膜的脂质组成的实质性变化。阳离子抗菌肽的优势是它们迅速杀死靶细胞，异常的广谱活性以及对某些更严重的抗生素耐药性病原体的活性。使用抗菌肽作为抗生素的主要障碍是它们的毒性或育核细胞的能力。我们采取了一种通过单L-和D氨基酸取代的两种不同类别的抗菌肽的两种不同类别的抗微生物肽的两亲性，疏水性和结构进行系统改变的方法。通过这种方法，我们能够与抗菌活性相结合，即增加抗菌活性并大大降低或消除对正常细胞的毒性（通过溶血活性测量）。我们在两种不同的结构类抗菌肽中发现了铅化合物，一种14个残基环状2型肽和26个沉积物1螺旋肽，具有临床潜力，作为广谱抗生素。两类化合物的同时开发将最快地提高我们对这些肽作用机理的了解，以及对微生物膜的选择性的共同要求。需要进一步优化我们从头设计的铅化合物，以确保我们在保持高治疗指数的同时获得最佳的抗菌活性。关键目标：1）确定非极性面中心的最佳阳性残留物类型，以提高环环2片和1螺旋肽的特异性； 2）选择了最好的阳性残留物来消除溶血活性，我们可以增加疏水性以改善抗菌活性，同时保持高治疗指数； 3）证明我们的肽对一系列人类细胞系无毒； 4）通过结构测定（固态NMR）显示我们两类抗菌肽在膜中的位置； 5）在两个动物模型中，我们的肽对铜绿假单胞菌的挑战表现出体内功效； 6）将我们的研究扩展到其他严重细菌感染的动物模型。 公共卫生相关性：许多相关细菌对传统抗生素具有抗性细菌的戏剧性和不断增长的出现现在是人类健康中的一个主要问题。由于经典抗生素的广泛使用，抗生素耐药性已引起。因此，通过扩大住院和越来越积极的治疗来治疗医院感染的成本已上涨至美国约300亿美元，因此，经济动机需要采用新颖的抗生素。