Unravelling the Structural and Molecular Basis Responsible for the Anti-Biofilm Activity of Zosteric Acid
作者:Cristina Cattò、Silvia Dell’Orto、Federica Villa、Stefania Villa、Arianna Gelain、Alberto Vitali、Valeria Marzano、Sara Baroni、Fabio Forlani、Francesca Cappitelli
DOI:10.1371/journal.pone.0131519
日期:——
The natural compound zosteric acid, or p-(sulfoxy)cinnamic acid (ZA), is proposed as an alternative biocide-free agent suitable for preventive or integrative anti-biofilm approaches. Despite its potential, the lack of information concerning the structural and molecular mechanism of action involved in its anti-biofilm activity has limited efforts to generate more potent anti-biofilm strategies. In this study a 43-member library of small molecules based on ZA scaffold diversity was designed and screened against Escherichia coli to understand the structural requirements necessary for biofilm inhibition at sub-lethal concentrations. Considerations concerning the relationship between structure and anti-biofilm activity revealed that i) the para-sulfoxy ester group is not needed to exploit the anti-biofilm activity of the molecule, it is the cinnamic acid scaffold that is responsible for anti-biofilm performance; ii) the anti-biofilm activity of ZA derivatives depends on the presence of a carboxylate anion and, consequently, on its hydrogen-donating ability; iii) the conjugated aromatic system is instrumental to the anti-biofilm activities of ZA and its analogues. Using a protein pull-down approach, combined with mass spectrometry, the herein-defined active structure of ZA was matrix-immobilized, and was proved to interact with the E. coli NADH:quinone reductase, WrbA, suggesting a possible role of this protein in the biofilm formation process.
天然化合物带状疱疹酸或对-(硫氧)肉桂酸(ZA)被认为是一种不含生物杀灭剂的替代药剂,适用于预防性或综合性抗生物膜方法。尽管ZA具有潜力,但由于缺乏有关其抗生物膜活性的结构和分子作用机制的信息,因此限制了开发更有效的抗生物膜策略的努力。在这项研究中,我们设计了一个由 43 个成员组成的基于ZA 支架多样性的小分子化合物库,并针对大肠杆菌进行了筛选,以了解在亚致死浓度下抑制生物膜所需的结构要求。对结构与抗生物膜活性之间关系的考虑表明:i) 利用分子的抗生物膜活性并不需要对位硫氧酯基团,肉桂酸支架才是抗生物膜性能的关键;ii) ZA 衍生物的抗生物膜活性取决于羧酸阴离子的存在,因此也取决于其供氢能力;iii) 共轭芳香系统对 ZA 及其类似物的抗生物膜活性至关重要。通过蛋白质牵引法和质谱法,ZA 的活性结构被基质固定,并被证明与大肠杆菌 NADH:醌还原酶 WrbA 相互作用,这表明该蛋白质可能在生物膜形成过程中发挥作用。