Orientational Pathways during Protein Translocation through Polymer-Modified Nanopores

Area of Science:

• Biophysics
• Nanotechnology
• Biochemistry

Background:

• Protein translocation through nanopores is vital for biotech, biomolecular analysis, and medicine.
• Interpreting translocation signals and understanding governing parameters remain challenging.
• A deeper understanding of macromolecule-nanopore interactions is crucial.

Purpose of the Study:

• Investigate the interplay of protein charge regulation, orientation, and nanopore surface modifications.
• Characterize protein translocation through nanopores modified with weak polyacids.
• Identify critical parameters governing protein translocation efficiency.

Main Methods:

• Utilized a theoretical framework to model acid-base reactions of titratable amino acids.
• Simulated translocation of various proteins (GFP, β-lactoglobulin, lysozyme, RNase).
• Analyzed pH-dependent interactions and free energy landscapes within modified nanopores.

Main Results:

• Protein charge regulation significantly impacts translocation dynamics.
• pH-dependent interactions create complex free energy landscapes affecting translocation efficiency.
• Protein isoelectric point, size, and morphology are significant factors in translocation behavior.

Conclusions:

• Protein charge regulation and nanopore surface chemistry are critical for controlling translocation.
• pH-responsive nanopores can be designed for controlled protein loading and release.
• This research offers new avenues for protein delivery, separation, and sensing applications.