Atomic-scale modeling of the interaction between short polypeptides and carbon surfaces

Area of Science:

• Computational chemistry
• Materials science
• Biophysics

Background:

• Peptide-surface interactions are crucial for biomaterials and nanotechnology.
• Understanding adsorption mechanisms on carbon nanomaterials is key for applications.

Purpose of the Study:

• To compare peptide adsorption on graphene versus carbon nanotubes.
• To elucidate the molecular basis of peptide-surface binding affinity.
• To investigate peptide folding and stability upon adsorption.

Main Methods:

• In vitro peptide selection for high carbon affinity.
• Rigid docking using a genetic algorithm.
• Molecular dynamics simulations with OPLS-AA force fields.
• Analysis of solvation energy, hydrogen bonds, and hydrophobic contacts.

Main Results:

• Strong adhesion energy and significant nonpolar contact surface observed for both graphene and carbon nanotubes.
• Tryptophan and isoleucine residues are key for strong binding, with tryptophan dominating.
• The peptide exhibits multiple stable configurations and enhanced intramolecular stability on carbon nanotubes.
• Histidine and tryptophan arrangements facilitate adaptation to both surfaces.

Conclusions:

• Peptide adsorption on carbon surfaces is driven by hydrophobic interactions and specific residue binding.
• Carbon nanotubes offer multiple stable binding configurations, potentially explaining experimental surface specificity.
• The peptide's ability to adopt diverse structures enhances its binding to carbon nanomaterials.