KnowVolution of the Polymer-Binding Peptide LCI for Improved Polypropylene Binding

Area of Science:

• Biotechnology
• Materials Science
• Protein Engineering

Background:

• Polymer surface functionalization via polymer-binding peptides is crucial for immobilizing biomolecules.
• Understanding peptide-surface-solvent interactions is key for designing effective adhesion promoters.
• Current limitations hinder the full potential of polymer-binding peptides due to incomplete molecular interaction knowledge.

Purpose of the Study:

• To engineer a polymer-binding peptide with enhanced stability and binding affinity to polypropylene (PP) surfaces.
• To gain molecular insights into peptide-PP interactions in the presence of surfactants using a novel approach.
• To develop robust peptides for PP surface functionalization under challenging process conditions.

Main Methods:

• Employed Knowledge-gaining directed evolution (KnowVolution), combining directed evolution and computational design.
• Investigated the binding of liquid chromatography peak I peptide (LCI) to PP in the presence of Triton X-100 surfactant.
• Identified key amino acid positions governing peptide-PP binding under competitive surfactant conditions.

Main Results:

• Identified 8 key amino acid positions influencing LCI binding to PP with Triton X-100.
• Developed a variant (KR-2) with a 5.4-fold increased binding affinity to PP in 1 mM Triton X-100.
• Achieved a maximum binding capacity of 8.8 pmol/cm² for the KR-2 variant on PP surfaces.

Conclusions:

• The KnowVolution approach successfully engineered a robust polymer-binding peptide (LCI variant KR-2).
• This variant demonstrates enhanced PP binding and stability in the presence of relevant surfactant concentrations.
• The developed peptides offer a promising solution for efficient PP surface functionalization in applications like detergents.