Identification of Chemical Compounds That Inhibit the Function of Histidyl-tRNA Synthetase from Pseudomonas aeruginosa

Authors

Yanmei Hu, The University of Texas Rio Grande Valley
Stephanie O. Palmer, The University of Texas Rio Grande Valley
Sara Robles, The University of Texas Rio Grande Valley
Tahyra Resto, The University of Texas Rio Grande ValleyFollow
Frank Dean, The University of Texas Rio Grande ValleyFollow
James M. Bullard, The University of Texas Rio Grande Valley

Document Type

Article

Publication Date

1-2018

Abstract

Pseudomonas aeruginosa histidyl-tRNA synthetase (HisRS) was selected as a target for antibiotic drug development. The HisRS protein was overexpressed in Escherichia coli and kinetically evaluated. The KM values for interaction of HisRS with its three substrates, histidine, ATP, and tRNAHis, were 37.6, 298.5, and 1.5 μM, while the turnover numbers were 8.32, 16.8, and 0.57 s-1, respectively. A robust screening assay was developed, and 800 natural products and 890 synthetic compounds were screened for inhibition of activity. Fifteen compounds with inhibitory activity were identified, and the minimum inhibitory concentration (MIC) was determined for each against a panel of nine pathogenic bacteria. Each compound exhibited broad-spectrum activity. Based on structural similarity and MIC results, four compounds, BT02C02, BT02D04, BT08E04, and BT09C11, were selected for additional analysis. These compounds inhibited the activity of HisRS with IC50 values of 4.4, 9.7, 14.1, and 11.3 µM, respectively. Time-kill studies indicated a bacteriostatic mode of inhibition for each compound. BT02D04 and BT08E04 were noncompetitive with both histidine and ATP, BT02C02 was competitive with histidine but noncompetitive with ATP, and BT09C11 was uncompetitive with histidine and noncompetitive with ATP. These compounds were not observed to be toxic to human cell cultures.

Comments

Original published version available at https://doi.org/10.1177/2472555217722016

Under a Creative Commons license

Recommended Citation

Hu, Y., Palmer, S. O., Robles, S. T., Resto, T., Dean, F. B., & Bullard, J. M. (2018). Identification of Chemical Compounds That Inhibit the Function of Histidyl-tRNA Synthetase from Pseudomonas aeruginosa. SLAS discovery : advancing life sciences R & D, 23(1), 65–75. https://doi.org/10.1177/2472555217722016

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Publication Title

SLAS Discovery

DOI

https://doi.org/10.1177/2472555217722016