Interfacial and emulsifying properties of designed β-strand peptides

Area of Science:

• Biochemistry and Materials Science
• Focus on peptide structure-function relationships and interfacial phenomena.

Background:

• Amphipathic β-strand peptides are investigated for their potential as novel biosurfactants.
• Understanding their behavior at interfaces is crucial for application development.

Purpose of the Study:

• To investigate the pH-dependent structural and surfactant properties of a series of amphipathic β-strand peptides.
• To evaluate their performance in emulsification and interfacial film formation.

Main Methods:

• Utilized electronic circular dichroism (ECD) for structural analysis.
• Assessed surface activity, interfacial mechanics, droplet sizing, and zeta potential.
• Varied pH to control peptide molecular charge from ±4 to 0.

Main Results:

• Peptides form polyproline-type helices when highly charged and may adopt β-hairpins when uncharged.
• Uncharged peptides form strong interfacial films but lead to large droplet sizes due to flocculation.
• Highly charged peptides show low interfacial coverage but good emulsifying activity.
• Optimal emulsification occurs at intermediate charge states, balancing zeta potential and binding affinity.

Conclusions:

• The emulsifying properties of β-strand peptides are reported for the first time.
• Peptide charge significantly impacts interfacial behavior and emulsification efficiency.
• These findings are vital for developing β-strand peptides as effective biosurfactants.