Design and Synthesis of a Biotinylated Chemical Probe for Detecting the Molecular Targets of an Inhibitor of the Production of the Pseudomonas aeruginosa Virulence Factor Pyocyanin

Abstract

Abstract:Pseudomonas aeruginosa is a human pathogen associated with a variety of life-threatening nosocomial infections. This organism produces a range of virulence factors which actively cause damage to host tissues. One such virulence factor is pyocyanin, known to play a crucial role in the pathogenesis of P. aeruginosa infections. Previous studies had identified a novel compound capable of strongly inhibiting the production of pyocyanin. It was postulated that this inhibition results from modulation of an intercellular communication system termed quorum sensing, via direct binding of the compound with the LasR protein receptor. This raised the possibility that the compound could be an antagonist of quorum sensing in P. aeruginosa, which could have important implications as this intercellular signaling mechanism is known to regulate many additional facets of P. aeruginosa pathogenicity. However, there was no direct evidence for the binding of the active compound to LasR (or any other targets). Herein we describe the design and synthesis of a biotin-tagged version of the active compound. This could potentially be used as an affinity-based chemical probe to ascertain, in a direct fashion, the active compound's macromolecular biological targets, and thus better delineate the mechanism by which it reduces the level of pyocyanin production.

Aza-BODIPY probe for selective visualization of cyclooxygenase-2 in cancer cells

“…Compound 2 was obtained from the reaction of sodium azide with 2-(2-(2-chloroethoxy)ethoxy)ethanol that give quantitative yield. 46 Aer that, 2 was undergone esterication with indomethacin to give compound 3. In another part, amino aza-BODIPY 4 47 was amide coupled with propiolic acid to obtain alkyne substituted aza-BODIPY 5.…”

Discovery of an inhibitor of the production of the Pseudomonas aeruginosa virulence factor pyocyanin in wild-type cells

“…This opportunistic pathogen is well known to be a challenging infection to completely eradicate in infected patients due to high levels of intrinsic resistance to a wide variety of antibiotics [ 1 – 6 ] and the tendency of P. aeruginosa cells to form antibiotic-resistant biofilms [ 7 – 9 ]. The incidence of multidrug-resistant P. aeruginosa infections is on the rise on a global scale [ 8 – 10 ] and this bacterium is now considered to have joined the ranks of the ‘superbugs’ [ 1 ]. Thus, there is an urgent need to discover new therapeutic strategies to combat P. aeruginosa infections [ 1 – 12 ].…”

“…Pyocyanin is an important redox active small molecule virulence factor which is widely considered to play a crucial role in the pathogenesis of P. aeruginosa infections ( Fig. 1 ) [ 8 – 9 17 – 18 ]. The inhibition of pyocyanin production has been identified as an attractive antivirulence strategy for the treatment of P. aeruginosa infections [ 8 – 9 19 ].…”

Targeting virulence factors as an antimicrobial approach: Pigment inhibitors

“…Perez and O'Brien first developed a novel series of nonnatural irreversible antagonists of P. aeruginosa LasR, and compound 76 was identified to suppress the expression of pyocyanin and biofilm formation in PAO1 and PA14 . In addition, Spring and Baker described the design and synthesis of a biotin‐tagged version of the active compound ( 77 ) to probe the level of pyocyanin production . The functions of nitric oxide (NO) in downstream processes in bacteria, such as biofilm dispersal, motility, virulence, and antimicrobial defense systems, has received enough attention, and Kumar and Kutty reported the design and synthesis of hybrid compounds based on AHL signaling molecules and NO donors as anti‐infective agents.…”

“…158 In addition, Spring and Baker described the design and synthesis of a biotin-tagged version of the active compound (77) to probe the level of pyocyanin production. 159 The functions of nitric oxide (NO) in downstream processes in bacteria, such as biofilm dispersal, motility, virulence, and antimicrobial defense systems, has received enough attention, and Kumar and Kutty reported the design and synthesis of hybrid compounds based on AHL signaling molecules and NO donors as anti-infective agents. Therefore, derivatives 78 and 79 displayed a less familiar performance against the production of pyocyanin at 100 μM.…”