Structural Investigations of Biofilm Matrices for Novel Antibiofilm Strategies

项目摘要/摘要 该项目将结合分子动力学模拟和其他类型的分子力学计算 用不同的实验方法表征条件致病菌形成的生物膜 属于洋葱伯克霍尔德氏菌复合体(BCC)和肺炎克雷伯氏菌。细菌生物膜 在感染中构成严重关切，因为它们增加了对抗微生物疗法的耐药性。 在生物膜中，细菌生活在由各种大分子组成的水合基质中，尤其是 多糖类，这是其形成的主要原因。了解生物膜基质的细节 结构在设计治疗感染的新策略方面可以发挥重要作用。这是我们的主要目标 这项提案是对继续目前资助的NIH研究(GM123283)的请求，该研究基于 在当前项目中获得的表征物种产生的多糖的结构的结果 BCC和肺炎克雷伯菌。这些聚合物包含一簇非极性的鼠李糖残基，可以提供 链的极性较弱，表明可能在凝胶中形成疏水连接区- 与其生物膜基质的结构相似，并可能构成生物膜破坏的目标。 在已有研究成果的基础上，我们将从实验两个方面探索以下研究方向 并通过计算机建模： 1)研究伯克霍尔德氏菌和克雷伯氏菌产生的不同结构的鼠李糖多糖。 研究它们的形态和聚集趋势，目的是模拟它们的生物膜基质 建筑。 2)基质多糖与参与群体感应系统的分子的相互作用将是 研究确定基质在细胞间通讯中的作用。 3)将使用三个系统来探索通过使用特定代理来削弱矩阵体系结构的可能性， 都是针对基质连接区而设计的：i)含鼠李糖残基的寡糖；ii)特异性 已通过噬菌体展示程序发现的可与细菌结合的多肽 多糖；iii)合成的糖多肽与选定的多肽结合鼠李糖残基 第二点进行了调查)。通过添加这些测试分子，将研究生物膜基质形态的变化 细菌培养。

Project Summary/Abstract This project will combine molecular dynamics simulations and other types of molecular mechanics calculations with various experimental methods to characterize the biofilms formed by opportunistic pathogen species belonging to the Burkholderia cepacia Complex (BCC) and by Klebsiella pneumoniae. Bacterial biofilms constitute a serious concern in infections since they confer increased resistance towards antimicrobial therapies. In biofilms, bacteria live within a hydrated matrix composed of various macromolecules, and in particular polysaccharides, which are primarily responsible for its formation. Understanding the details of biofilm matrix structure can be of significant utility in designing novel strategies for treating infections. This is the main objective of this proposal, which is a request for the continuation of a currently funded NIH study (GM123283) based on the results acquired in this current project characterizing the structure of polysaccharides produced by species of the BCC and K. pneumoniae. These polymers contain clusters of non-polar rhamnose residues that confer a less polar character to the chains, suggesting the possible formation of hydrophobic juncture zones in the gel- like structures of their biofilm matrices, and possibly constituting targets for biofilm disruption. On the basis of the results already achieved, the following research lines will be explored both experimentally and by computer modelling: 1) Structurally different rhamnose-rich polysaccharides produced by Burkholderia and Klebsiella will be studied to investigate their morphology and aggregation tendency, with the objective of modeling their biofilm matrix architectures. 2) The interactions of matrix polysaccharides with molecules participating in quorum sensing systems will be studied to define the role of the matrix in cell-cell communication. 3) The possibility of weakening matrix architecture by using specific agents will be explored using three systems, all designed to target matrix junction zones: i) oligosaccharides containing rhamnose residues; ii) specific peptides which have already been found, by means of phage display procedures, to bind bacterial polysaccharides; iii) synthetic glycopeptides obtained binding rhamnose residues to selected peptides investigated in point ii). Changes in biofilm matrix morphologies will be studied by adding these test molecules to bacterial cultures.