Lecture 6: Protein Folding

Question 0

Explain the “folding funnel” diagram

Answer 0

It shows that as the protein becomes more and more folded, entropy decreases.
This is due to the hydrophobic effect

Question 1

How is folding hierarchical?

Answer 1

As a certain number of translated amino acids appear from the ribosome, they fold up…when another group of amino acids appears from the ribosome, they fold up (with the first group), etc…
*This also explains the concept of “repeating motifs”

Question 2

What are the amino acids that destabilize a chain? Why do they destabilize the chain?

Answer 2

Gly- has no “r” group which allows greater rotation around psi and phi
Asn, Ser, Asp- have “r” groups that interact with the main chain (backbone)
Pro- has “r” group that is part of the main chain (causes kinks in alpha-helices)

Question 3

Can proteins undergo metamophosis?

Answer 3

Yes

Question 4

Explain the concept of “content dependent” in regards to protein folding

Answer 4

The same sequence of amino acids can take on different shapes in different proteins