Dynamic control of protein-protein interactions

Area of Science:

• Materials Science
• Biotechnology
• Electrochemistry

Background:

• Protein-protein interactions are crucial in biological systems.
• Controlling these interactions with external stimuli is a key challenge in biosensing.
• Polypyrrole (PPy) is a conductive polymer with potential for bio-interfacing.

Purpose of the Study:

• To demonstrate the electrical control of protein-protein interactions using antibody-doped polypyrrole.
• To investigate the mechanism of reversible antigen binding.
• To develop a sensing platform for real-time protein concentration measurements.

Main Methods:

• Doping polypyrrole with anti-human fibronectin antibodies (alphaFN).
• Applying voltage to control fibronectin (FN) binding and dissociation.
• Utilizing staircase potential electrochemical impedance spectroscopy (SPEIS) for characterization.

Main Results:

• Electrically controlled binding and dissociation of fibronectin to alphaFN-doped PPy was achieved by altering applied voltage.
• SPEIS confirmed that oxidation promoted FN binding and reduction facilitated FN dissociation.
• Reversible antigen binding is attributed to charge minimization in the polymer films, not suppression of hydrophobic forces.

Conclusions:

• Antibody-doped PPy offers a novel platform for electrically controllable protein-protein interaction modulation.
• The sensing platform enables rapid, repeated, and specific measurements of protein concentrations.
• This technology has potential applications in diagnostics and biomolecular analysis.