Biochemical Characterization of Glutamate Racemase—A New Candidate Drug Target against Burkholderia cenocepacia Infections

Abstract

The greatest obstacle for the treatment of cystic fibrosis patients infected with the Burkholderia species is their intrinsic antibiotic resistance. For this reason, there is a need to develop new effective compounds. Glutamate racemase, an essential enzyme for the biosynthesis of the bacterial cell wall, is an excellent candidate target for the design of new antibacterial drugs. To this aim, we recombinantly produced and characterized glutamate racemase from Burkholderia cenocepacia J2315. From the screening of an in-house library of compounds, two Zn (II) and Mn (III) 1,3,5-triazapentadienate complexes were found to efficiently inhibit the glutamate racemase activity with IC50 values of 35.3 and 10.0 μM, respectively. Using multiple biochemical approaches, the metal complexes have been shown to affect the enzyme activity by binding to the enzyme-substrate complex and promoting the formation of an inhibited dimeric form of the enzyme. Our results corroborate the value of glutamate racemase as a good target for the development of novel inhibitors against Burkholderia.

Chemical, Metabolic, and Cellular Characterization of a FtsZ Inhibitor Effective Against Burkholderia cenocepacia

“…During the last few years, we focused our attention on this topic, proposing new targets, such as the glutamate racemase (Israyilova et al, 2016), new strategies, such as the inhibition of quorum sensing (Scoffone et al, 2016;Buroni et al, 2018) and new drugs (Scoffone et al, 2014), to fight B. cenocepacia infections. We found that the benzothiadiazole derivative C109 is highly effective against B. cenocepacia (Scoffone et al, 2015) and other Gram-negative and-positive bacteria, including Mycobacterium abscessus (Hogan et al, 2018).…”

The role of diazacrown ether in the enhancement of the biological activity ofsilver nanoparticles

“…The DC sample was dissolved in distilled water without further sonication. The growth was determined by the resazurin method after 24 h of incubation at 37 • C; 30 µ L of resazurin solution (0.01%; Sigma Aldrich) was added to each well and the microplates were reincubated at 37 • C for about 4 h. If the color change from blue to pink, it indicated the growth of bacteria, and the minimum inhibitory concentration (MIC) was determined as the lowest concentration of the active agents that prevented this change in color [23,24].…”

In vitro antimicrobial activity of 2,4-Diacetyl-5-hydroxy-5-methyl-3-phenyl-N-oxyethyl1-cyclohexenylamine

“…All the experiments were performed thrice and DMSO was used as control. Minimum inhibitory concentration values were determined by using Resazurin microplate assay in 96 well microtitre plates [5]. For each test bacterium, density of 24 hour fresh broth culture was adjusted to 0.5 McFarland in Mueller-Hinton medium.…”