Identification of potential inhibitors of sortase A: Binding studies, in-silico docking and protein-protein...

Area of Science:

• Microbiology
• Drug Discovery
• Structural Biology

Background:

• Enterococcus faecalis (Ef) is a major cause of multidrug-resistant (MDR) infections, with Sortase A (EfSrtA) crucial for biofilm formation and a promising drug target.
• Identifying novel inhibitors of EfSrtA is critical for combating Ef-associated diseases.

Purpose of the Study:

• To identify and characterize potential inhibitors of Enterococcus faecalis Sortase A (EfSrtA_∆59).
• To investigate the binding interactions of lead compounds with EfSrtA_∆59 and its protein partners.

Main Methods:

• Cloning, expression, and purification of EfSrtA_∆59.
• In-silico molecular docking and protein-protein docking studies.
• Fluorescence and circular dichroism (CD) spectroscopy for binding analysis.
• Thermo stability assays and STRING database analysis for interaction partners.

Main Results:

• Docking revealed benzylpenicillin, cefotaxime, pantoprazole, and valsartan bind to EfSrtA_∆59 at a conserved site with similar interactions.
• Spectroscopic studies confirmed the binding of these ligands to EfSrtA_∆59, validated by CD experiments.
• Sequence analysis identified Ef_1091, Ef_1093, and Ef_2658 as interaction partners; homology modeling and docking explored these interactions.

Conclusions:

• Benzylpenicillin, cefotaxime, pantoprazole, and valsartan are potential inhibitors of EfSrtA_∆59, offering new therapeutic avenues against MDR Enterococcus faecalis.
• Understanding EfSrtA_∆59 interactions with its partners provides insights into bacterial virulence mechanisms and potential drug targets.