Development of antipathogenic agents targeting biosynthetic enzyme and receptor of cyclic peptide quormone

以硫内酯或内酯肽作为自诱导物的群体感应在许多革兰氏阳性菌中是常见的，并且控制某些病原体（如大肠杆菌）的毒力表达。例如，在一个实施例中，葡萄球菌、肠球菌和葡萄球菌。在这种情况下，有效性的抗病毒剂针对这种类型的群体感应已被提出。本研究采用随机筛选微生物次级代谢产物和设计肽拮抗剂两种方法，寻找革兰氏阳性菌中环肽介导的群体感应抑制剂。为了筛选，我们已经建立了一个有效的筛选系统，使用明胶酶测定粪肠球菌。到目前为止，我们已经测试了一千多种真菌和放线菌的提取物，以及一百多种天然和合成的化合物，并发现了几种化合物可以有效地抑制葡萄球菌agr和肠球菌fsr群体感应系统中的一种或两种。对于P的设计 ...更多信息 肽拮抗剂，我们采取了我们独创的方法，称为反向丙氨酸扫描，在此过程中，更有效的拮抗剂逐步从受体结合支架[Ala 4，5，6，8，9，11]] Z-GBAP（GBAP是E. faecalis FSR系统）。因此，发现GBAP中的第5、9和11位残基是拮抗剂药效团，并且利用这些信息，我们最终创建了一种有效的拮抗剂，命名为ZBzl-YAA 5911（IC 80 =0. 1μM）。为了阐明ZBzl-YAA 5911作为抗感染剂的可用性，用无晶状体兔眼内炎模型评估该肽对眼内炎的功效。结果表明，ZBzl-YAA 5911抑制了E. ZBzi-YAA 5911可将粪球菌从房水中释放到玻璃体腔中超过一个数量级，并且还显著降低了动物的视网膜损伤，这表明ZBzi-YAA 5911可用作抗病原体剂，以减弱毒力表达而不是消除机会病原体。少

Quorum sensing with thiolactone or lactone peptide as an autoinducer is common among a number of Gram-positive bacteria and controls the expression of virulence in some pathogens, e. g., staphylococci, enterococci and listeria. In this context, the validity of anti-pathogenic agents targeting this type of quorum sensing has been proposed. In this study, to aim inhibitors targeting the cyclic peptide-mediated quorum sensing in Gram-positive bacteria, we have been employing two approaches, that are random screening of microbial secondary metabolites and drug design of peptide antagonists. For the screening, we have established an efficient screening system using an gelatinase assay of Enterococcus faecalis. Thus far, we have tested more than a thousand extracts of fungi and actinomycetes and more than a hundred natural and synthetic compounds and found several compounds to efficiently inhibit either or both staphylococci agr and enterococci fsr quorum sensing systems. For the design of p … More eptide antagonist, we took our original approach, called reverse alanine scanning, during which more potent antagonists were led step by step from receptor-binding scaffold that is[ Ala4, 5, 6, 8, 9, 11]] Z-GBAP(GBAP is an autoinducing lactone peptide of E. faecalis fsr system). In consequence, 5th, 9th and 11th residues in GBAP were found to be antagonist pharmacophore and with this information, we have eventually created a potent antagonist, named ZBzl-YAA5911(IC80=0. 1μM). To elucidate the availability of ZBzl-YAA5911 as an anti-infective agent, the efficacy of this peptide for endophthalmitis was assessed with an aphakic rabbit endophthalmitis model. As a result, ZBzl-YAA5911 suppressed the translocation of E. faecalis from the aqueous humor into the vitreous cavity more than one order magnitude and also significantly reduced the retinal damage of animals, suggesting that ZBzi-YAA5911 would be useful as anti-pathogenic agent to attenuate virulence expression more than eliminate the opportunistic pathogen. Less