Exploring the interaction between Mycobacterium tuberculosis enolase and human plasminogen using computational...

Area of Science:

• Microbiology
• Structural Biology
• Biochemistry

Background:

• Surface-localized microbial enolases bind human plasminogen, playing a role in pathogen infection cycles.
• Mycobacterium tuberculosis (Mtb) enolase binding to human plasminogen may impact granuloma stability during infection.

Purpose of the Study:

• This study aimed to identify and characterize the specific residues on Mtb enolase responsible for binding human plasminogen.
• The research sought to understand the molecular interactions involved in Mtb enolase-plasminogen binding for potential therapeutic intervention.

Main Methods:

• Structural modeling of Mtb enolase was performed.
• Protein-protein docking simulations predicted the binding pose between Mtb enolase and human plasminogen.
• Site-directed mutagenesis was used to experimentally validate the role of identified residues in plasminogen binding.

Main Results:

• The study identified two consecutive lysine residues, Lys-193 and Lys-194, as critical for plasminogen binding.
• A triple mutant Mtb enolase (K193A + K194A + K429A) showed a 40% reduction in plasminogen binding.
• These substitutions significantly reduced binding without causing major secondary structure changes.

Conclusions:

• Specific lysine residues on Mtb enolase are essential for its interaction with human plasminogen.
• Targeting these Mtb enolase residues could be a strategy to inhibit pathogen binding and potentially treat tuberculosis.
• Sequence comparison suggests selective targeting of Mtb enolase over human enolase is feasible.