Interactions of Protein with Grafted Poly(ethylene oxide) Layer in Two Setups: A Molecular Dynamics Simulation Study

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Computational Biophysics

Background:

• Developing effective antifouling materials requires understanding protein-surface interactions.
• Existing experimental methods for studying these interactions differ from physiological conditions.

Purpose of the Study:

• To compare protein-surface interactions under experimental and physiological conditions using molecular dynamics simulations.
• To investigate the influence of grafting density and protein orientation on C1q protein interactions with poly(ethylene oxide) (PEO) grafted onto graphene.

Main Methods:

• Atomistic molecular dynamics simulations were employed.
• Simulations modeled interactions between C1q protein fragments and PEO chains grafted onto graphene at varying densities.

Main Results:

• The lowest PEO grafting density yielded contradictory results due to restricted protein space.
• Medium PEO grafting density demonstrated the most favorable interactions between C1q and the PEO layer.
• C1q protein's secondary structure was altered, showing β-sheet destabilization and 310-helix formation.
• Protein orientation significantly impacted C1q-PEO layer interactions.

Conclusions:

• Medium grafting densities of PEO on graphene provide optimal conditions for antifouling properties.
• Protein structural changes and orientation are critical factors in protein-surface interactions.
• Molecular dynamics simulations offer valuable insights into antifouling material design.