Lecture 6 Protein Folding I

Question 1

Protein folding is a

Answer 1

Highly cooperative process

Question 2

4 Determinants of Folding

Answer 2

1. Secondary structure allows for efficient packing
2. Folding is hierarchical
3. Folding is to some degree context dependent
4. Hydrophobic effect - most important

Question 3

Most important determinant of folding

Answer 3

Hydrophobic effect

Question 4

Hydrophobic effect

Answer 4

Folding determinant

Increased entropy of water adds to dynamics to folding

Question 5

If you allow unraveled chain to fold…

Answer 5

It will find native conformation

Question 6

Native conformation is determined by

Answer 6

Its sequence

Question 7

Folding funnel

Answer 7

Beginning of helix formation and collapse

Energy funnel

Question 8

Folding funnel 4 Events

Answer 8

1. Rapid formation of secondary structure
2. Formation of domains through cooperative aggregation (concept ‘folding nuclei’)
3. Formation of assembled domains (concept of ‘molten globule’)
4. Adjustment of conformation

Question 9

‘Folding Nuclei’

Answer 9

Formation of domains through cooperative aggregation

Question 10

‘Molten globule’

Answer 10

Formation of assembled domains

Question 11

Accessory Proteins

Answer 11

Molecular chaperones, get proteins out of conformationally dead ends

Question 12

For protein folding to occur Gibbs Free Energy has to be

Answer 12

Negative

Question 13

Delta H

Answer 13

Enthalpy
Change of heat energy
If change in heat, heat is released

Question 14

Delta S

Answer 14

If chain is negative, has increased order

Question 15

AA have different

Answer 15

Propensities for forming secondary structures

Question 16

AA and context-dependent

Answer 16

Many sequences can adopt alternative conformations in different proteins
-context of overall fold can put constraints on it