Protein Structure and Protein Folding

Question 1

This is formed when elements of secondary structure are connected by turns or regions of less ordered structure called loops or coils.

Answer 1

Supersecondary structure

Question 2

What are the 4 common motifs of supersecondary structures?

Answer 2

helix-turn-helix, strand-helix-strand
, beta hairpin, Greek hairpin

Question 3

Supersecondary structure elements combine to form..

Answer 3

domains

Question 4

There are independently folded regions that often possess a specific function within the protein.

Answer 4

Domains

Question 5

What aspect of a domain helps to make it stable?

Answer 5

Hydrophobic core

Question 6

This domain family is mostly amphipathic helices with side chains packed closely together within a hydrophobic core.

Answer 6

a-domain family

Question 7

What domain family can pack between non-adjacent helices?

Answer 7

a-domain family

Question 8

What domain family does a horseshoe fold belong in?

Answer 8

a/B family

Question 9

What domain family would usually fold to form a basket or barrel shaped proteins?

Answer 9

Antiparallel B family

Question 10

What domain family does a retinol binding protein belong to?

Answer 10

Antiparallel B family

Question 11

This domain is a small polypeptide chain of 53 amino acids and usually known as an epidermal growth factor

Answer 11

EGF

Question 12

This domain has 245 amino acids arranged in 2 domains.

Answer 12

Chymotrypsin

Question 13

These domains have a characteristic pattern of 3 internal disulfide bridges within a region of about 85 amino acid residues.

Answer 13

Kringle domains

Question 14

Where are proteins made?

Answer 14

Ribosome

Question 15

Where are the instructions for protein folding embedded in?

Answer 15

Primary amino acid sequence

Question 16

These interactions are individually weak in proteins, but collectively make a significant contribution to protein conformational stability.

Answer 16

Non covalent interactions

Question 17

These are proteins that assist other proteins to fold properly during or after protein synthesis.

Answer 17

Chaperone proteins

Question 18

These are proteins that have misfolded and can cause other proteins to change shape to form aggregates that can cause brain damage.

Answer 18

Prion proteins (proteins infectious agent)

Question 19

This is the term for an abnormally folded protein.

Answer 19

Amyloid

Question 20

Alzheimer’s disease and type 2 diabetes are caused by:

Answer 20

Misfolding/aggregation of proteins

Question 21

Protein folding is directed largely by what?

Answer 21

Internal hydrophobic residues (aka the hydrophobic core) - these residues end up aggregating to form the hydrophobic core.

Question 22

What is the sequence of events in folding a potein?

Answer 22

1) formation of secondary structures
2) subdomains/supersecondary structures form
3) subdomains come together to form partly folded domain aka a molten globule (which can still rearrange)
4) final domain structure emerges, and small conformational adjustments