Cationic Clitoria ternatea Seed Peptide as a Potential Novel Bioactive Molecule

Area of Science:

• Plant Biochemistry
• Peptide Chemistry
• Microbiology

Background:

• Limited investigation into cationic peptides from Clitoria ternatea beyond cyclotides.
• Fabaceae family climber Clitoria ternatea is a source of various biologics.
• Need to explore novel bioactive peptides from C. ternatea seeds.

Purpose of the Study:

• To isolate and characterize novel cationic peptides from C. ternatea seeds.
• To evaluate the antimicrobial and antioxidant potential of these peptides.
• To elucidate the functional characteristics of newly identified peptides.

Main Methods:

• Purification of cationic peptide using cost-effective procedures.
• Analysis via electrophoresis and mass spectrometry (MS).
• Antimicrobial assays against bacterial and fungal pathogens.
• In vitro antioxidant assays and physicochemical characterization.
• Tandem MS for peptide sequencing.

Main Results:

• An 8.5 kDa cationic peptide was purified from C. ternatea seeds.
• The peptide exhibited antimicrobial activity against Candida albicans, Staphylococcus aureus, Aeromonas hydrophila, and Escherichia coli (MIC 8-32 μg/ml).
• Activity remained stable at pH 5-8 and moderate heat (70-80°C), but was sensitive to proteases.
• Demonstrated concentration-dependent antioxidant activity (free-radical scavenging and ferric-reducing capacity).
• Tandem MS revealed low sequence coverage, suggesting a novel peptide distinct from known cyclotides.

Conclusions:

• A novel cationic peptide of 8.5 kDa was identified from C. ternatea seeds.
• This peptide possesses significant antimicrobial and antioxidant activities.
• The findings provide insights into the functional characteristics of this new bioactive peptide.