Design of Novel Saposin-like Bacteriocins Using a Hybrid Approach.

Area of Science:

• Microbiology
• Biochemistry
• Drug Discovery

Background:

• Antibiotic resistance poses a significant global health threat, necessitating the development of alternative antimicrobial strategies.
• Bacteriocins, antimicrobial peptides, offer a promising alternative due to their distinct mechanisms of action, effective against resistant bacteria.
• Saposin-like bacteriocins, which target bacterial membranes, are a specific class with therapeutic potential.

Purpose of the Study:

• To construct and screen a library of hybrid saposin-like bacteriocins to identify novel antimicrobial agents.
• To investigate structure-activity relationships within saposin-like bacteriocins.
• To evaluate the antimicrobial efficacy of engineered bacteriocins against clinically relevant pathogens.

Main Methods:

• Generation of a hybrid peptide library by combining N- and C-terminal halves of seven native saposin-like leaderless bacteriocins.
• Synthesis of hybrid peptides using in vitro protein expression.
• Antimicrobial activity assays against a panel of pathogenic bacteria, including Gram-positive and Gram-negative species.

Main Results:

• Eleven novel hybrid bacteriocins exhibited antimicrobial activity.
• Several hybrids demonstrated altered antimicrobial spectra and increased potency compared to parent molecules.
• The lead hybrid, ISP26, showed potent inhibition against most tested Gram-positive bacteria and Acinetobacter baumannii, a nosocomial pathogen.

Conclusions:

• The engineered hybrid bacteriocin library provides valuable insights into bacteriocin design and screening.
• ISP26 represents a promising candidate for further development as a novel antimicrobial agent against antibiotic-resistant bacteria.
• This approach highlights the potential of bacteriocin engineering to address the challenge of antimicrobial resistance.