Direction-dependent mechanical unfolding and green fluorescent protein as a force sensor

Area of Science:

• Biophysics
• Computational Biology
• Protein Dynamics

Background:

• Understanding protein mechanical unfolding is crucial for molecular biology.
• Experimental studies observe distinct unfolding pathways and forces.
• Computational models are needed to simulate and predict these behaviors.

Purpose of the Study:

• To investigate the mechanical unfolding of green fluorescent protein (GFP) using an Ising-like model.
• To explore how different pulling directions affect unfolding pathways and forces.
• To propose a novel force sensor based on mechanical unfolding properties.

Main Methods:

• Utilized an Ising-like model for protein simulation.
• Simulated mechanical unfolding of GFP under directional pulling.
• Analyzed unfolding pathways and calculated unfolding forces.

Main Results:

• The model reproduced experimentally observed major and minor unfolding pathways of GFP when pulled from its ends.
• Varying the pulling direction yielded accurate magnitudes and rankings of unfolding forces.
• Direction-dependent unfolding forces at equilibrium were identified.

Conclusions:

• The Ising-like model effectively captures protein mechanical unfolding dynamics.
• Pulling direction is a critical factor influencing protein mechanical stability.
• A new force sensor concept leveraging directional unfolding forces was proposed.