Subtractive proteomics unravel the potency of D-alanine-D-alanine ligase as the drug target for Burkholderia pseudomallei

Int J Biol Macromol. 2025 Jun:314:144106. doi: 10.1016/j.ijbiomac.2025.144106. Epub 2025 May 18.

Abstract

Melioidosis, also known as Whitmore's disease, is caused by the deadly pathogen Burkholderia pseudomallei and remains a significant global health concern, particularly in South Asia. The disease is contracted through exposure to contaminated soil, water, air, and food. Infected individuals often present with abscesses in internal organs such as the lungs, spleen, and liver, and in soft tissues, with severe cases leading to septic shock and acute pneumonia. The rising incidence and mortality rates, coupled with B. pseudomallei's ability to form biofilms and develop resistance to antibiotics like cephalosporins, make treatment increasingly challenging. This highlights the urgent need for novel therapeutic approaches. D-Alanine-D-Alanine ligase (Ddl), a crucial enzyme involved in the final stage of bacterial cell wall synthesis, which protects the pathogen from the hostile cellular environment of the host. While many bacteria have two isoforms of this enzyme, B. pseudomallei possesses only the DdlB isoform, presenting a significant vulnerability. Our study represents the first successful attempt to target DdlB through a combination of molecular docking and molecular dynamics simulations. These investigations provide strong evidence that Conivaptan acts as an effective inhibitor of DdlB, offering a novel therapeutic approach for combating melioidosis.

Keywords: Burkholderia pseudomallei; D-alanine-D-alanine ligase; Drug repurposing; Target identification.

MeSH terms

  • Anti-Bacterial Agents* / chemistry
  • Anti-Bacterial Agents* / pharmacology
  • Bacterial Proteins* / antagonists & inhibitors
  • Bacterial Proteins* / chemistry
  • Bacterial Proteins* / metabolism
  • Burkholderia pseudomallei* / drug effects
  • Burkholderia pseudomallei* / enzymology
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Melioidosis / drug therapy
  • Melioidosis / microbiology
  • Molecular Docking Simulation
  • Molecular Dynamics Simulation
  • Peptide Synthases* / antagonists & inhibitors
  • Peptide Synthases* / chemistry
  • Peptide Synthases* / metabolism
  • Proteomics* / methods

Substances

  • D-alanylalanine synthetase
  • Peptide Synthases
  • Anti-Bacterial Agents
  • Enzyme Inhibitors
  • Bacterial Proteins