4 research outputs found
Correction to: The Asp99–Arg188 salt bridge of the Pseudomonas aeruginosa HemO is critical in allowing conformational flexibility during catalysis
Small Molecule Antivirulents Targeting the Iron-Regulated Heme Oxygenase (HemO) of <i>P. aeruginosa</i>
Bacteria require iron for survival
and virulence and employ several
mechanisms including utilization of the host heme containing proteins.
The final step in releasing iron is the oxidative cleavage of heme
by HemO. A recent computer aided drug design (CADD) study identified
several inhibitors of the bacterial HemOs. Herein we report the near
complete HN, N, CO, Cα, and Cβ chemical shift assignment
of the <i>P. aeruginosa</i> HemO in the absence and presence
of inhibitors (<i>E</i>)-3-(4-(phenylamino)phenylcarbamoyl)acrylic
acid (<b>3</b>) and (<i>E</i>)-<i>N</i>′-(4-(dimethylamino)benzylidene)
diazenecarboximidhydrazide (<b>5</b>). The NMR data confirm
that the inhibitors bind within the heme pocket of HemO consistent
with in silico molecular dynamic simulations. Both inhibitors and
the phenoxy derivative of <b>3</b> have activity against <i>P. aeruginosa</i> clinical isolates. Furthermore, <b>5</b> showed antimicrobial activity in the in vivo C. elegans curing assay. Thus, targeting virulence mechanisms required within
the host is a viable antimicrobial strategy for the development of
novel antivirulants
Iminoguanidines as Allosteric Inhibitors of the Iron-Regulated Heme Oxygenase (HemO) of <i>Pseudomonas aeruginosa</i>
New therapeutic targets
are required to combat multidrug resistant
infections, such as the iron-regulated heme oxygenase (HemO) of <i>Pseudomonas aeruginosa</i>, due to links between iron and virulence
and dependence on heme as an iron source during infection. Herein
we report the synthesis and activity of a series of iminoguanidine-based
inhibitors of HemO. Compound <b>23</b> showed a binding affinity
of 5.7 μM and an MIC<sub>50</sub> of 52.3 μg/mL against <i>P. aeruginosa</i> PAO1. An in cellulo activity assay was developed
by coupling HemO activity to a biliverdin-IXα-dependent infrared
fluorescent protein, in which compound <b>23</b> showed an EC<sub>50</sub> of 11.3 μM. The compounds showed increased activity
against clinical isolates of <i>P. aeruginosa</i>, further
confirming the target pathway. This class of inhibitors acts by binding
to an allosteric site; the novel binding site is proposed in silico
and supported by saturation transfer difference (STD) NMR as well
as by hydrogen exchange mass spectrometry (HXMS)