Download MendeleyInsights into the Inhibition ofAeromonas hydrophilad-Alanine-d-Alanine Ligase by Integration of Kinetics and Structural Analysis.
Zhang, Y., Gong, S., Wang, X., Muhammad, M., Li, Y., Meng, S., Li, Q., Liu, D., Zhang, H.(2020) J Agric Food Chem 68: 7509-7519
- PubMed: 32609505
- DOI: https://doi.org/10.1021/acs.jafc.0c00682
- Primary Citation of Related Structures:
6LL9 - PubMed Abstract:
Aeromonas hydrophila , a pathogenic bacterium, is harmful to humans, domestic animals, and fishes and, moreover, of public health concern due to the emergence of multiple drug-resistant strains. The cell wall has been discovered as a novel and efficient drug target against bacteria, and d-alanine-d-alanine ligase (Ddl) is considered as an essential enzyme in bacterial cell wall biosynthesis. Herein, we studied the A. hydrophila HBNUAh01 Ddl ( Ah Ddl) enzyme activity and kinetics and determined the crystal structure of Ah Ddl/d-Ala complex at 2.7 Å resolution. An enzymatic assay showed that Ah Ddl exhibited higher affinity to ATP ( K m : 54.1 ± 9.1 μM) compared to d-alanine ( K m : 1.01 ± 0.19 mM). The kinetic studies indicated a competitive inhibition of Ah Ddl by d-cycloserine (DCS), with an inhibition constant ( K i ) of 120 μM and the 50% inhibitory concentrations (IC 50 ) value of 0.5 mM. Meanwhile, structural analysis indicated that the Ah Ddl/d-Ala complex structure adopted a semi-closed conformation form, and the active site was extremely conserved. Noteworthy is that the substrate d-Ala occupied the second d-Ala position, not the first d-Ala position. These results provided more insights for understanding the details of the catalytic mechanism and resources for the development of novel drugs against the diseases caused by A. hydrophila .
Organizational Affiliation:
College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, P. R. China.
