Molecular capture in protein nanotubes.

Area of Science:

• Biomaterials Science
• Nanotechnology
• Protein Engineering

Background:

• Protein nanotubes offer potential for molecular capture due to their unique structure.
• Controlling ligand binding affinity and size selectivity is crucial for targeted applications.
• Layer-by-layer (LbL) assembly provides a versatile method for creating complex nanostructures.

Purpose of the Study:

• To develop protein nanotubes with adjustable molecular capturing capabilities.
• To investigate the influence of protein composition and assembly on nanotube properties.
• To demonstrate the selective capture of ligands and nanoparticles using engineered protein nanotubes.

Main Methods:

• Fabrication of protein nanotubes via alternating LbL assembly of poly-L-arginine (PLA) and human serum albumin (HSA) within a polycarbonate template.
• Characterization of nanotube structure, stability, and swelling behavior.
• Assessment of molecular capturing properties using various ligands (uranyl ion, dyes, ZnPP) and biotin-FITC, including studies with a recombinant HSA mutant and ligand displacement reactions.
• Demonstration of nanoparticle capture within the nanotubes.

Main Results:

• Robust protein nanotubes [(PLA/HSA)(3)] were successfully synthesized and characterized.
• The nanotubes exhibited controllable binding affinity for specific ligands, with a recombinant mutant showing enhanced ZnPP capture.
• Ligand replacement reactions were demonstrated, allowing for controlled release of captured molecules.
• Efficient capture of FITC-biotin and biotin-labeled nanoparticles was achieved, showcasing size-selective incorporation.

Conclusions:

• Protein nanotubes can be engineered with tunable ligand-binding affinity and size selectivity.
• LbL assembly offers a viable strategy for creating functional protein-based nanostructures.
• These protein nanotubes hold promise for applications in molecular separation, sensing, and targeted delivery.