The ribosome lowers the entropic penalty of protein folding

Here is a rewritten version of the passage at a 10th-grade reading level:

Most proteins begin to fold into their proper shapes while they are being made on the ribosome. Studies have shown that the way proteins fold during this process, and the energy involved, can be very different from how they fold when they are refolded outside of this process. Until now, it wasn't clear why the ribosome affects protein folding in this way.

In this study, we looked at the detailed structures of an unfolded protein both on and off the ribosome. We found that the ribosome causes the unfolded protein chain to spread out more and increases how much it interacts with water. This makes the protein chain less stable when it's on the ribosome compared to when it's alone. Tests using 19F NMR confirmed that this instability makes it easier for the protein to start folding on the ribosome, lowering the energy cost by up to 30 kcal/mol. This helps the protein form partially folded shapes, which are necessary for some proteins to reach their active forms. These effects also help protect the protein from unfolding due to mutations, suggesting that the ribosome plays an important role in how proteins evolve. By linking the structure and movement of the protein chain to how it folds and behaves after folding, our findings explain why protein folding on the ribosome is different from folding after translation is complete.