Department of Cell Biology and Molecular Genetics, University of Maryland at College Park, College Park, Maryland 20742, United States.
Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536, United States.
ACS Infect Dis. 2021 Jun 11;7(6):1713-1726. doi: 10.1021/acsinfecdis.1c00045. Epub 2021 Apr 19.
is a Gram-negative opportunistic pathogen that is frequently found in the airways of cystic fibrosis (CF) patients due to the dehydrated mucus that collapses the underlying cilia and prevents mucociliary clearance. During this life-long chronic infection, cell accumulates mutations that lead to inactivation of the gene that results in the constitutive expression of operon and the production of alginate exopolysaccharide. The viscous alginate polysaccharide further occludes the airways of CF patients and serves as a protective matrix to shield from host immune cells and antibiotic therapy. Development of inhibitors of alginate production by would reduce the negative impact from this viscous polysaccharide. In addition to transcriptional regulation, alginate biosynthesis requires allosteric activation by bis (3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) binding to an Alg44 protein. Previously, we found that ebselen (Eb) and ebselen oxide (EbO) inhibited diguanylate cyclase from synthesizing c-di-GMP. In this study, we show that EbO, Eb, ebsulfur (EbS), and their analogues inhibit alginate production. Eb and EbS can covalently modify the cysteine 98 (C98) residue of Alg44 and prevent its ability to bind c-di-GMP. However, with Alg44 C98 substituted with alanine or serine was still inhibited for alginate production by Eb and EbS. Our results indicate that EbO, Eb, and EbS are lead compounds for reducing alginate production by . Future development of these inhibitors could provide a potential treatment for CF patients infected with mucoid .
铜绿假单胞菌是一种革兰氏阴性机会性病原体，由于脱水的黏液会使下面的纤毛塌陷并阻止黏液纤毛清除，因此经常在囊性纤维化 (CF) 患者的气道中发现。在这种终身慢性感染过程中， 细胞会积累突变，导致 基因失活，从而导致 操纵子的组成性表达和藻酸盐胞外多糖的产生。粘性藻酸盐多糖进一步阻塞 CF 患者的气道，并作为一种保护基质，将 与宿主免疫细胞和抗生素治疗隔离开来。通过 抑制藻酸盐的产生会减少这种粘性多糖带来的负面影响。除了转录调控外，藻酸盐生物合成还需要二 (3'-5')-环二鸟苷单磷酸 (c-di-GMP) 与 Alg44 蛋白结合对其进行变构激活。以前，我们发现 ebselen (Eb) 和 ebselen 氧化物 (EbO) 抑制二鸟苷酸环化酶合成 c-di-GMP。在这项研究中，我们表明 EbO、Eb、ebsulfur (EbS) 及其类似物抑制藻酸盐的产生。Eb 和 EbS 可以共价修饰 Alg44 的半胱氨酸 98 (C98) 残基，阻止其与 c-di-GMP 结合。然而，Alg44 C98 被丙氨酸或丝氨酸取代后，仍被 Eb 和 EbS 抑制藻酸盐的产生。我们的结果表明，EbO、Eb 和 EbS 是减少 产生的藻酸盐的先导化合物。这些抑制剂的未来开发可为感染粘液型 的 CF 患者提供潜在的治疗方法。
