Trp-Cage Folding on Organic Surfaces.

Area of Science:

• Biophysics
• Computational Chemistry
• Materials Science

Background:

• Trp-cage is a stable, fast-folding artificial miniprotein.
• Its interactions with organic surfaces and impact on conformation are not well understood.

Purpose of the Study:

• Investigate Trp-cage folding and conformational changes on self-assembled monolayers (SAMs).
• Characterize the binding affinities and driving forces of these interactions.

Main Methods:

• Utilized replica-exchange molecular dynamics (REMD) and metadynamics (MetaD) simulations.
• Studied Trp-cage interactions with neutral (CH3) and anionic (COOH) SAMs.

Main Results:

• Trp-cage strongly binds to neutral CH3 surfaces (-25kT) via hydrophobic interactions.
• Trp-cage moderately adsorbs to anionic COOH interfaces (-7.6kT) through electrostatic attractions.
• SAMs induce intermediate Trp-cage conformations; aromatic group orientation differs between surface types.

Conclusions:

• Surface chemistry dictates Trp-cage binding strength and mechanism.
• Hydrophobic and electrostatic forces are key drivers of Trp-cage adhesion to SAMs.
• Trp-cage exhibits distinct conformational responses to different organic surfaces.