Lecture 6- Protein Folding I Flashcards Preview

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Flashcards in Lecture 6- Protein Folding I Deck (14)
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1
Q

Describe the different types of non-covalent interactions:

A

VdW- charges (e-) fluctuate around an atom, forming temporary dipole moments
electrostatic- charges on one atom interact with charges on another, as described by Coulomb’s law
hydrogen bonding- partial charges from hydrogen interact with Nitrogen and Oxygen
short range repulsion-

2
Q

Protein folding is a highly (random/cooperative) process

A

cooperative

3
Q

Secondary structure plays an important part in the ____ of proteins.

A

compact folding

4
Q

The conformation of a protein is the result of specific _____.

A

AA sequences

5
Q

How does hydrophobicity act as a determinant of folding?

A

Hydrophobic AAs tend to “cluster together” in pockets of hydrophobicity (usually found within the plasma membrane)

6
Q

Draw/describe the steps of protein folding.

A

1) Secondary structure is rapidly achieved (high E* state)
2) Format’n of hydrophobic domains (cooperative) leading to “core protein”
3) Formation of a molten globule
4) Adjustment of structure to native, low E* structure

7
Q

The dynamic conformational state between native protein and full-unfolded protein

A

Molten globule

8
Q

Why is the concept of the “molten globule” important?

A

The molten globule exists as the protein tries to find a low E*, highly ordered, thermodynamically stable structure

9
Q

What two major types of interactions determine protein folding?

A

Non-covalent and hydrophobic interactions

10
Q

Describe the characteristics of the “molten globule”

A

1) Presence of some 2* “native structure” elements - the beginnings of final form are taking shape
2) No specific 3* structure - no packing of side chains
3) Compact into the overall shape of the protein, but radius is still 10-30% larger than final native protein’s radius
4) Loosely packed hydrophobic core

11
Q

Repeating secondary structure present in many proteins that exhibit similar f(x)s

A

Domain

12
Q

Structural charachteristics of a protein (ex: repeated alpha-helices)

A

motif

13
Q

A specific functional region of a protein

A

domain (ex: antigen binding domain on an anti-body)

14
Q

List the “non-covalent” interactions responsible for protein folding:

A
  • van der Walls
  • electrostatic interaction
  • Hydrogen bonds
  • short range repulsion