Confinement effect on the structure and elasticity of proteins interfacing polymers

Area of Science:

• Biophysics
• Materials Science
• Surface Chemistry

Background:

• Ordered nanostructured surfaces offer unique environments for protein functionalization.
• Confinement effects on protein behavior are crucial for understanding biological processes and designing nanomaterials.

Purpose of the Study:

• To investigate the structural and elastic changes of fibrinogen and lysozyme proteins confined within poly(methyl methacrylate) nanopores.
• To elucidate the impact of pore size and macromolecular crowding on protein conformation and mechanical properties.

Main Methods:

• Utilized poly(methyl methacrylate) films with controlled nanopore sizes.
• Immobilized fibrinogen and lysozyme within the nanopores.
• Analyzed protein secondary structure changes using Fourier-transform infrared spectroscopy.
• Measured protein elasticity (modulus) under confinement.

Main Results:

• Fibrinogen exhibited minimal structural alteration and reduced stiffness in nanopores approximating its size.
• Lysozyme maintained a native-like structure but showed increased modulus in 15 nm pores due to reduced crowding.
• Confinement and crowding significantly influenced the conformation and elasticity of both proteins.

Conclusions:

• Nanopore confinement and macromolecular crowding distinctly affect the structure and elasticity of different proteins.
• Protein shape and size relative to pore dimensions are critical factors in determining confinement-induced changes.
• Findings provide insights into protein behavior at the nanoscale for applications in biomaterials and biosensing.