Functionalized Proline-Rich Peptides Bind the Bacterial Second Messenger c-di-GMP

Area of Science:

• Microbiology
• Biochemistry
• Drug Discovery

Background:

• Cyclic di-GMP (c-di-GMP) is a vital second messenger regulating bacterial pathogenesis, including biofilm formation and virulence.
• Targeting c-di-GMP is a promising strategy for combating bacterial infections.

Purpose of the Study:

• To identify novel molecules that bind to c-di-GMP.
• To investigate the potential of these molecules as inhibitors of bacterial biofilm formation.

Main Methods:

• Screening of a combinatorial peptide library to identify c-di-GMP binding peptides.
• Computational and Circular Dichroism (CD) spectroscopic studies to elucidate binding modes.
• Biological assays to evaluate the efficacy of identified peptides against bacterial biofilm growth.

Main Results:

• Identification of a proline-rich tetrapeptide (Gup-Gup-Nap-Arg) with selective binding to c-di-GMP in aqueous solution.
• Elucidation of a potential binding mode and design of a higher-affinity pentapeptide.
• Demonstration that the tetrapeptide inhibits biofilm formation in the opportunistic pathogen *Pseudomonas aeruginosa*.

Conclusions:

• Peptide-based molecules can effectively target c-di-GMP.
• The identified tetrapeptide is a promising lead compound for developing new anti-biofilm agents.
• This approach offers a novel strategy to combat bacterial infections by disrupting essential cellular processes.