Inhibition of Interspecies Bacterial Quorum Sensing

描述(由申请者提供)：这个项目是化学、结构生物学和细菌遗传学的综合成果，重点是酶LuxS。LuxS负责在许多不同种类的致病菌中产生关键的群体感应分子AI-2。一个长期的目标是更全面地了解物种间的群体感应功能，并提出一种新的方法来控制一些最严重的细菌病原体的致病性，如霍乱弧菌和炭疽杆菌。LuxS生产DPD，这是自发相互转换分子和硼酸酯的来源，统称为AI-2。设计、合成和评价LUXS的底物类似物、过渡态类似物和基于机理的抑制剂是本项目的主要目标。这些设计将基于蛋白质结构信息和所提出的LuxS的作用机制。所设计的抑制剂将在体外进行活性优化，然后在体内进行有效性和有利的药代动力学改进。有效的抑制剂将与天然的LuxS结晶，以提供活性酶/抑制剂相互作用的详细结构。高通量筛选化合物文库将与布罗德研究所合作，使用体内和体外建立的LuxS活性检测方法。我们的目标是确定新的结构类型，可以作为LUXS的抑制剂。X射线结晶学研究将提供新的抑制剂与LUXS相互作用的信息，这些信息将反馈到抑制剂设计中。在对高灵敏的哈维氏弧菌生物测定进行初步评估后，有希望的抑制剂将在两种临床重要病原体--鼠伤寒沙门氏菌和霍乱弧菌中进行测试。这些研究可能导致新型广谱细菌控制剂的开发。根据一种不会杀死细菌的新原理，这种方法不太可能像大多数传统抗菌药那样受到耐药性快速发展的影响。该项目旨在发现新的小分子，通过抑制AI-2信号系统来抑制细菌的群体感应。AI-2系统似乎可以控制广泛的细菌致病性，有效的抑制剂将作为探针在不同物种以及多物种群体中研究这一系统。具有适当药理学特性的有效抑制剂将成为控制病原菌的全新方法的候选药物，作为传统抗生素疗法的补充或替代。

DESCRIPTION (provided by applicant): This project is an integrated effort of chemistry, structural biology, and bacterial genetics with a focus on the enzyme LuxS. LuxS is responsible for producing the key quorum sensing molecules, AI-2, in many different species of pathogenic bacteria. A long range goal is a more complete understanding of the inter- species quorum sensing function with the implication of a new approach to control the pathogenicity of some of the most serious bacterial pathogens, such as Vibrio cholerae and Bacillus anthracis. LuxS produces DPD, the source of spontaneously interconverting molecules and borate diesters that are collectively called AI-2. Design, synthesis, and evaluation of substrate analog, transition state analog, and mechanism-based inhibitors of LuxS is a major goal of this project. The designs will be based on protein structural information and the proposed mechanism of action of LuxS. The designed inhibitors will be optimized for activity in vitro, and then refined for effectiveness and favorable pharmacokinetics in vivo. Effective inhibitors will be crystallized with native LuxS to provide a detailed structure of the active enzyme/inhibitor interaction. High throughput screening of compound libraries will be undertaken in collaboration with the Broad Institute, using a well-established assays for LuxS activity in vivo and in vitro. The goal is to identify new structural types that can function as inhibitors of LuxS. An X-ray crystallographic effort will provide information on the interaction of new inhibitors with LuxS, and this information will feed back into the inhibitor design. After initial evaluation in the highly sensitive bioluminescent Vibrio harveyi bioassay, promising inhibitors will be tested in the two clinically important pathogens, Salmonella typhimurium and Vibrio cholerae. These studies may result in the development of novel broad-spectrum bacterial control agents. Working by a new principle that does not kill the bacteria, this approach is unlikely to suffer from the rapid development of resistance as observed with most traditional anti-bacterials. This project aims to discover new small molecules that will inhibit quorum sensing in bacteria through the inhibition of the AI-2 signaling system. The AI-2 system appears to control pathogenicity over a broad spectrum of bacteria, and potent inhibitors will serve as probes to investigate this system in different species as well as in multi-species colonies. Potent inhibitors with appropriate pharmacological properties will be candidates for an entirely new approach to control of pathogenic bacteria, as a supplement or replacement for conventional antibiotic therapy.