Specific Interactions and Environment Flexibility Tune Protein Stability under Extreme Crowding.

Area of Science:

• Biophysics
• Computational Biology
• Protein Science

Background:

• Macromolecular crowding is crucial for protein mobility and stability within cells.
• Accurately predicting protein thermal stability requires understanding excluded volume, specific interactions, and crowder thermal behavior.

Purpose of the Study:

• To investigate the factors influencing protein melting under extreme crowding using lysozyme as a model system.
• To dissect the contributions of environmental flexibility and electrostatic interactions to protein thermal stability.

Main Methods:

• Utilizing advanced molecular simulations.
• Complementing simulations with experimental calorimetric measurements.

Main Results:

• Demonstrated that the temperature-dependent flexibility of macromolecular crowders plays a key role.
• Showed that specific interactions significantly modulate protein thermal stability.
• Found that these factors alleviate the stabilizing effect of static excluded volume.

Conclusions:

• Protein thermal stability in crowded environments is complex, influenced by dynamic and interactive factors.
• The flexibility and specific interactions of crowders are critical determinants of protein melting.
• Static volume effects alone do not fully capture the observed changes in protein stability.