<p><i>E. coli</i> MG1655 was incubated in MHB at 37°C for 1.5 hr in the presenc... more <p><i>E. coli</i> MG1655 was incubated in MHB at 37°C for 1.5 hr in the presence of SM10 (<b>A</b>) alone or in combination with the iron chelator dipyridyl. The cells were washed and incubated with HPF, for quantification of hydroxyl radicals (<b>A, B</b>) or processed to quantify DNA breaks (<b>C</b>) with the TUNEL assay.</p
*<p>Relative to DMSO treatment.</p><p>Data are the averages of at least 3 indep... more *<p>Relative to DMSO treatment.</p><p>Data are the averages of at least 3 independent cultures (± SE).</p
DNA repair pathways in bacteria that use homologous recombination involve the formation and subse... more DNA repair pathways in bacteria that use homologous recombination involve the formation and subsequent resolution of Holliday junction (HJ) intermediates. We have previously identified several hexameric peptides that bind to HJs and interfere with HJ processing enzymes in vitro. The peptide WRWYCR and its D-amino acid stereoisomer wrwycr, are potent antibacterial agents. These hexapeptides must form homodimers in order to interact stably with HJs, and inhibit bacterial growth, and this represents a potential limitation. Herein we describe a disulfide bond-independent inhibitor, WRWYRGGRYWRW and its D-stereoisomer wrwyrggrywrw. We have characterized these single-chain, linear analogs of the hexapeptides, and show that in addition to effectively binding to HJs, and inhibiting the activity of DNA repair enzymes that process HJs, they have equal or greater potency against Gram-positive and Gram-negative bacterial growth. The analogs were also shown to cause DNA damage in bacteria, and disrupt the integrity of the bacterial cytoplasmic membrane. Finally, we found that they have little toxicity toward several eukaryotic cell types at concentrations needed to inhibit bacterial growth.
<p><i>E. coli</i> MG1655 was incubated in MHB at 37°C for 1.5 hr in the presenc... more <p><i>E. coli</i> MG1655 was incubated in MHB at 37°C for 1.5 hr in the presence of SM10 (<b>A</b>) alone or in combination with the iron chelator dipyridyl. The cells were washed and incubated with HPF, for quantification of hydroxyl radicals (<b>A, B</b>) or processed to quantify DNA breaks (<b>C</b>) with the TUNEL assay.</p
*<p>Relative to DMSO treatment.</p><p>Data are the averages of at least 3 indep... more *<p>Relative to DMSO treatment.</p><p>Data are the averages of at least 3 independent cultures (± SE).</p
DNA repair pathways in bacteria that use homologous recombination involve the formation and subse... more DNA repair pathways in bacteria that use homologous recombination involve the formation and subsequent resolution of Holliday junction (HJ) intermediates. We have previously identified several hexameric peptides that bind to HJs and interfere with HJ processing enzymes in vitro. The peptide WRWYCR and its D-amino acid stereoisomer wrwycr, are potent antibacterial agents. These hexapeptides must form homodimers in order to interact stably with HJs, and inhibit bacterial growth, and this represents a potential limitation. Herein we describe a disulfide bond-independent inhibitor, WRWYRGGRYWRW and its D-stereoisomer wrwyrggrywrw. We have characterized these single-chain, linear analogs of the hexapeptides, and show that in addition to effectively binding to HJs, and inhibiting the activity of DNA repair enzymes that process HJs, they have equal or greater potency against Gram-positive and Gram-negative bacterial growth. The analogs were also shown to cause DNA damage in bacteria, and disrupt the integrity of the bacterial cytoplasmic membrane. Finally, we found that they have little toxicity toward several eukaryotic cell types at concentrations needed to inhibit bacterial growth.
Uploads
Papers by Jason Rostron