Selection of Peptides that Associate with Dye-Conjugated Solid Surfaces in a pH-Dependent Manner Using cDNA Display

Area of Science:

• Biotechnology
• Chemical Biology
• Molecular Recognition

Background:

• Peptides recognizing artificial materials are crucial for biotechnology and chemical biology.
• Reversible peptide aptamers, which bind targets conditionally, are of particular interest.

Purpose of the Study:

• To select peptide aptamers that recognize a phenolphthalein derivative (PhP) in a pH-dependent manner.
• To explore the potential of these aptamers for applications like protein purification.

Main Methods:

• Utilized an in vitro display method (cDNA display) with a biased DNA library encoding aromatic amino acids.
• Performed seven rounds of selection from over 10^10 peptide species against PhP-modified surfaces.
• Employed control experiments to elucidate the binding mechanisms and specificity.

Main Results:

• Selected peptide aptamers, such as LV59 (LVFLIWWM), that bind to PhP-modified supports in neutral buffer.
• Observed prompt dissociation of peptides under basic conditions due to PhP structural and charge changes.
• Identified that binding is primarily driven by pi-stacking and hydrophobic interactions, with some sequence specificity.

Conclusions:

• Developed pH-sensitive peptide aptamers capable of reversible binding to a phenolphthalein derivative.
• Demonstrated the potential utility of this specific peptide-PhP interaction for practical applications, such as affinity-based protein purification.