TY - JOUR
T1 - Synergy Screening Identifies a Compound That Selectively Enhances the Antibacterial Activity of Nitric Oxide
AU - Chou, Wen Kang
AU - Vaikunthan, Mathini
AU - Schröder, Hendrik V.
AU - Link, A. James
AU - Kim, Hahn
AU - Brynildsen, Mark P.
N1 - Funding Information:
This work was supported by the generosity of Helen Shipley Hunt ∗71 through a Focused Research Team award on Precision Antibiotics, and Princeton SEAS Lidow Senior Thesis Fund. HS gratefully acknowledges support by the Deutsche Forschungsgemeinschaft (DFG Research Fellowship, GZ: SCHR 1659/1-1). The funders had no role in the preparation of the manuscript or decision to publish, and this content is solely the responsibility of the authors and does not necessarily represent the views of the funding agencies.
Funding Information:
We thank the National BioResource Project (National Institute of Genetics, Japan) for its support of the distribution of the Keio Collection, and Professor Thomas Silhavy for providing the imp4213 mutant. In addition, we thank Professors Mohamed Donia and Joel Freundlich for their suggestions on this project. Funding. This work was supported by the generosity of Helen Shipley Hunt ?71 through a Focused Research Team award on Precision Antibiotics, and Princeton SEAS Lidow Senior Thesis Fund. HS gratefully acknowledges support by the Deutsche Forschungsgemeinschaft (DFG Research Fellowship, GZ: SCHR 1659/1-1). The funders had no role in the preparation of the manuscript or decision to publish, and this content is solely the responsibility of the authors and does not necessarily represent the views of the funding agencies.
Publisher Copyright:
© Copyright © 2020 Chou, Vaikunthan, Schröder, Link, Kim and Brynildsen.
PY - 2020/8/25
Y1 - 2020/8/25
N2 - Antibiotic resistance poses a serious threat to global health. To reinforce the anti-infective arsenal, many novel therapeutic strategies to fight bacterial infections are being explored. Among them, anti-virulence therapies, which target pathways important for virulence, have attracted much attention. Nitric oxide (NO) defense systems have been identified as critical for the pathogenesis of various bacteria, making them an appealing therapeutic target. In this study, we performed chemical screens to identify inhibitors of NO detoxification in Escherichia coli. We found that 2-mercaptobenzothiazole (2-MBT) can potently inhibit cellular detoxification of NO, achieving a level of inhibition that resembled the effect of genetically removing Hmp, the dominant detoxification enzyme under oxygenated conditions. Further analysis revealed that in the presence of NO, 2-MBT impaired the catalysis of Hmp and synthesis of Hmp and other proteins, whereas in its absence there were minimal perturbations to growth and protein synthesis. In addition, by studying the structure-activity relationship of 2-MBT, we found that both sulfur atoms in 2-MBT were vital for its inhibition of NO detoxification. Interestingly, when 2-mercaptothiazole (2-MT), which lacked the benzene ring, was used, differing biological activities were observed, although they too were NO dependent. Specifically, 2-MT could still prohibit NO detoxification, though it did not interfere with Hmp catalysis; rather, it was a stronger inhibitor of protein synthesis and it reduced the transcript levels of hmp, which was not observed with 2-MBT. Overall, these results provide a strong foundation for further exploration of 2-MBT and 2-MT for therapeutic applications.
AB - Antibiotic resistance poses a serious threat to global health. To reinforce the anti-infective arsenal, many novel therapeutic strategies to fight bacterial infections are being explored. Among them, anti-virulence therapies, which target pathways important for virulence, have attracted much attention. Nitric oxide (NO) defense systems have been identified as critical for the pathogenesis of various bacteria, making them an appealing therapeutic target. In this study, we performed chemical screens to identify inhibitors of NO detoxification in Escherichia coli. We found that 2-mercaptobenzothiazole (2-MBT) can potently inhibit cellular detoxification of NO, achieving a level of inhibition that resembled the effect of genetically removing Hmp, the dominant detoxification enzyme under oxygenated conditions. Further analysis revealed that in the presence of NO, 2-MBT impaired the catalysis of Hmp and synthesis of Hmp and other proteins, whereas in its absence there were minimal perturbations to growth and protein synthesis. In addition, by studying the structure-activity relationship of 2-MBT, we found that both sulfur atoms in 2-MBT were vital for its inhibition of NO detoxification. Interestingly, when 2-mercaptothiazole (2-MT), which lacked the benzene ring, was used, differing biological activities were observed, although they too were NO dependent. Specifically, 2-MT could still prohibit NO detoxification, though it did not interfere with Hmp catalysis; rather, it was a stronger inhibitor of protein synthesis and it reduced the transcript levels of hmp, which was not observed with 2-MBT. Overall, these results provide a strong foundation for further exploration of 2-MBT and 2-MT for therapeutic applications.
KW - HTSS
KW - Hmp
KW - NO
KW - high-throughput synergy screening
KW - thiazole
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U2 - 10.3389/fbioe.2020.01001
DO - 10.3389/fbioe.2020.01001
M3 - Article
C2 - 32984281
AN - SCOPUS:85090772733
SN - 2296-4185
VL - 8
JO - Frontiers in Bioengineering and Biotechnology
JF - Frontiers in Bioengineering and Biotechnology
M1 - 1001
ER -