Discrete protein dynamics enable long-range communication.

Area of Science:

• Biophysics
• Molecular Biology
• Computational Biology

Background:

• Allostery enables proteins to function as molecular logic gates by transmitting signals between distant sites.
• Focalized allostery transmits information without altering protein structure outside of the input/output sites.
• Long-distance correlated motions in proteins are crucial for focalized allostery but are not well understood.

Purpose of the Study:

• To investigate the physical properties enabling long-distance information transfer in proteins.
• To understand how proteins maintain signal integrity against thermal noise.

Main Methods:

• Introduction of a Variable-Well Dihedral (VWD) model Hamiltonian.
• Focusing on the nonlinearity of local interactions within a polymer model.
• Analyzing the discreteness of internal degrees of freedom.

Main Results:

• The VWD model demonstrates that tuning physical parameters leads to focalized allostery.
• Increased discreteness of internal degrees of freedom enhances focalized allostery.
• Real proteins exhibit highly discrete internal dynamics, supporting the model's findings.

Conclusions:

• Protein allostery relies on discrete internal motions for robust, long-distance information transfer.
• This mechanism parallels the efficiency of digital over analog signal processing in noisy environments.
• The findings provide insights into the physical basis of allosteric regulation in proteins.