Biotechnology Bulletin ›› 2024, Vol. 40 ›› Issue (6): 319-329.doi: 10.13560/j.cnki.biotech.bull.1985.2023-1228

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Screening of CTX-M-14-type Ultra-broad-spectrum β-lactamase Inhibitors Based on Pharmacophore Modelling

WANG Meng-fan1(), ZHAO Zi-yu1, WANG Chun-guang1, LIU Ting-yu2, CHEN Xi1, ZHANG Tie1()   

  1. 1. College of Animal Medicine, Hebei Agricultural University, Baoding 071000
    2. General Station of Livestock Breeding Work, Hebei Province, Shijiazhuang 050049
  • Received:2024-01-02 Online:2024-06-26 Published:2024-06-24
  • Contact: ZHANG Tie E-mail:mengfan202312@163.com;zhangtie1998@163.com

Abstract:

【Objective】 Development of inhibitors against cefotaxime-hydrolase-14(CTX-M-14)-type ultra-broad-spectrum β-lactamases(ESBLs)to mitigate the serious harm caused by bacterial drug resistance. 【Method】 DiscoveryStudio Visualizer(DS Visualizer)was used to construct a receptor structure-based pharmacophore(SBP)and a ligand common feature-based qualitative pharmacophore model(HIPHOP), and the validated models were used as query conditions for virtual screening of the ZINC database targeting CTX-M-14 protein, and glycyrrhizic acid(GL), a monomer component of traditional Chinese medicine(TCM)with good fitting scores, was obtained. The related force analysis, molecular dynamics simulation and binding free energy calculation were carried out to analyse the binding mode, binding capacity and stability of glycyrrhizic acid and CTX-M-14 protein. Finally, the antibacterial sensitizing activity, enzyme inhibition and enzyme inhibition of glycyrrhizic acid were investigated by the combined bacterial inhibition assay and enzyme kinetic assay. 【Result】 Glycyrrhizic acid, a single component of traditional Chinese medicine, mainly formed hydrogen bonds and van der Waals forces with multiple amino acid residues in the active centre of CTX-M-14 protein, and the docking fraction and binding free energy of the two were -10 kcal/mol and -22.06 kcal/mol, respectively. Glycyrrhizic acid synergistically interacted with cefotaxime sodium(FICI ≤ 0.5); glycyrrhizic acid competitively inhibited the hydrolysis of the substrate antibiotic by β-lactamase, and the enzyme inhibition and protection rate of cefotaxime sodium reached 58.53%, which was close to that of clavulanic acid(60.98%). 【Conclusion】 The Chinese medicine monomer glycyrrhizic acid can bind stably to CTX-M-14 protein and increase the sensitivity of multi-drug-resistant Escherichia coli E320 and recombinant protein-positive bacterium BL-21 to cefotaxime sodium by competitively inhibiting the hydrolysis of the substrate antibiotic by β-lactamase, so as to achieve a reduction in the quantity and increase in the effectiveness of the antibiotic.

Key words: glycyrrhizic acid, CTX-M-14, pharmacophore modelling, simulation of molecular dynamics, combined bacterial inhibition