Lecture 3: Elements of protein structure II

Question 1

What makes up domains?

Answer 1

Independently folded regions that often posses a specific binding function

Domains usually have a hydrophobic core with its surface bing hydrophilic
——> difference in polarity helps to form the strict in (aq) environments

Question 2

What are super secondary structures?

Answer 2

Are elements of secondary structures which are connected by turns, loops or coils which make up super secondary structures
- combinations of helix & sheets are common elements of super secondary structures.

Question 3

What are examples of non-covalent interactions which stabile the tertiary structure of a protien?

Answer 3

• Metal ion cooridnation
• Hydrophobic interactions
• Disulphide bonds
• side chain hydrogen bonding
• Electrostatic attraction

Question 4

What are the three pathways in which a protein can be shaped?

Answer 4

• Chaperone indépendant = protein can fold itself without help from a chaperone
• Chaperone dependant = protein requires the help from a chaperone to fold correctly
• Chaporin dependant= = protein requires the presence of a chaporin to help fold.

Question 5

What is a chaperone?

Answer 5

A small protein which helps proteins to fold up because they prevent the hydrophobic regions from being attracted to other proteins

Question 6

What is a chaporonin?

Answer 6

A large, multi-protein structures shaped like a barrel which allows proteins to be folded within.

Question 7

What is the formation of secondary structure e.g a-helix & b-sheet called?

Answer 7

Nucleation

Question 8

What are the steps in the possible protein folding pathway?

Answer 8

1. Formatin of secondary structures by a process of nucleation
2. Nuclei come together to form domains
3. Domains come together
4. Through a few adjustments, a compact native protein is formed

Question 9

How do proteins fold?

Answer 9

Folding is directed largely by its internal hydrophobic residues, which form and internal core, which hydrophillic residues are on the outside - solvent exposed

Question 10

What are some examples of misfolded proteins that cause disease?

Answer 10

Prions = are infectious abnormal(misfolded) proteins that cause degenerate brain disease
—> cause normal proteins to bcm abnormal
Amyloid= an abnormal protein that contributes to Alzehimers disease