The ribosome lowers the entropic penalty of protein folding (Nature)

The study published in Nature investigates the role of the ribosome in protein folding, specifically how it reduces the entropic penalty associated with this process. Researchers found that during co-translational folding, the ribosome expands the unfolded nascent chain and increases its solvation, leading to an entropic destabilization of the chain compared to when it is isolated. This destabilization can lower the entropic penalty of folding by up to 30 kcal/mol, facilitating the formation of partially folded intermediates essential for some proteins to achieve their active conformations. The ribosome's influence on nascent chain structure and dynamics is crucial for understanding the thermodynamics of co-translational protein folding, which differs significantly from in vitro refolding studies. The findings suggest that the ribosome not only aids in proper protein folding but also protects nascent chains from mutations that could lead to misfolding. This research provides insights into the physical basis of co-translational folding and its implications for protein evolution and stability.

- The ribosome significantly lowers the entropic penalty of protein folding.

- Co-translational folding differs from in vitro refolding, with unique intermediates formed.

- Ribosome interactions lead to structural expansion and increased solvation of nascent chains.

- The study highlights the ribosome's protective role against mutation-induced unfolding.

- Findings enhance understanding of the thermodynamics involved in protein folding processes.