Lecture 8

Question 1

WHat AA is not allowing for rotation of bond in secondary structures?

Answer 1

Proline

Question 2

Does the tertiary structure depend on the primary structure?

Answer 2

Yes, unlike the secondary structure

Question 3

What are the main stabilizing forces of tertiary and quartenary structures?

Answer 3

Electrostatic attractions, hydrogen bonds and Van der Waals attraction

Question 4

Whats special about multi domain proteins?

Answer 4

Have multiple hydrophobic cores
Side chain interactions are mostly intradomain focused

Question 5

What is the molten globule state?

Answer 5

Intermediate in folding, somesecondary structures exist but not fully formed. This is because it is easier to explore alternative folds.

Question 6

What are folding energetics?

Answer 6

Normally folding is exergonic. It looks for the total minimum and chaperones help it overcome local minimum, by re-folding

Question 7

What are common tasks of chaperones?

Answer 7

Catalyze folding through partial unfolding
Prevents aggregates
Can also prevent folding

Question 8

Whats special about chaperones in heat? (Hsp70)

Answer 8

Many chaperones are heat shock chaperones -> upregulated in heat because high heat leads to protein unfolding
(active co-translationally)

Question 9

Whats special about Hsp60?

Answer 9

Works on misfolded proteins
(cavity with hydrophobic surfaces, unfolds and refolds proteins until they dont have any hydrophillic surfaces on the outside left)

Question 10

Why would chaperones prevent folding in some cases?

Answer 10

For import into mitochondria etc.

Question 11

Whats the transport signal ?

Answer 11

KDEL