Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BIOC192 > Lecture 6: FOLDING A PROTEIN > Flashcards

Lecture 6: FOLDING A PROTEIN Flashcards

1
Q

What is super secondary structure?

A

Elements of secondary structure - helices and strands are connected by turns or by regions of less ordered structure called loops to coils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are common motifs of supersecondary structure?

A

helix-turn-helix, beta hairpin, greek key ad strand-helix-strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are examples of helix-turn-helix?

A

DNA binding proteins and calcium binding proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What helix-turn-helix protein has a more complicated turn?

A

Calcium binding proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Are beta hairpins common?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the structure of the beta hairpin?

A

Antiparallel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What varies in beta hairpins?

A

Length and number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens in a beta hairpin?

A

A single strand has nothing to bond with but the other strand in the hairpin coming back is able to bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are examples of beta hairpins?

A

Bovine pancreatic trypsin inhibitor and snake venom toxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does snake venom toxin have?

A

2 beta hairpins and one other strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is involved in a greek key?

A

4 antiparallel strands

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Is strand-helix-strand common?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Where are the helix and strands in stran-helix-strand found?

A

In different planes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How are the strands stabilised in strand-helix-strand?

A

By the side chains of the helix and other strand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do super secondary structure elements combine to form?

A

Domains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are domains?

A

Independently folded regions that often possess a specific function within a protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does a protein domain typically have?

A

A hydrophobic core and the hydrophilic parts of the protein are arranged on the surface in contact or near solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is very important for protein stability?

A

Hydrophobic core

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do small proteins contain?

A

Usually one domain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do larger proteins (>250 residues) contain?

A

May have multiple domains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are protein families based on?

A

Structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the protein families?

A

Alpha domain family, alpha/beta family and antiparallel beta family

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the structure of the alpha domain family?

A

Mostly helical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the alpha domain family include?

A

4 helix bundles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How are 4 helix bundles arranged?
Slightly tilted to allow side chains to fit tight. The hydrophobic residues are found on the interior and hydrophilic on the exterior causing a hydrophobic core to form
26
What is amphipathic?
When something is partly hydrophobic and partly hydrophilic
27
What does the alpha domain also include?
Globin fold
28
What does the global fold have?
Amphipathic helices wth side chains packed closely together within a hydrophobic core. Packing occurs between non-adjacent helices
29
What is the alpha/beta family?
Mix of alpha and beta structure including strand-helix-strand repeated many times
30
What does the barrel structure have?
Bottom and middle internal layers of side chains hydrophobic and pointing out is he hydrophilic side chains which commonly form the active site
31
What is the horseshoe fold?
A 16 strand helix motif repeat where all of the strands are parallel
32
What is antiparallel beta family?
Mostly anti-parallel beta structure with no helices, just turns
33
What is an example of antiparallel beta family?
Retinal binding protein
34
What is the structure of retinal binding protein?
It has a hydrophobic inside of a barrel with the strands wrapping around a molecular held inside. The end of the tip of retinol is a hydrophilic hydroxyl group which sticks outside the barrel slightly
35
What does nature do with domain?
Common structural domains are repeated and combined to make different types of proteins
36
What are common protein domains?
EGF, chymotrypsin, kringle domain and calcium-binding domain
37
How are proteins synthesised?
As linear, non-branching polymers that have to fold into a 3 dimensional functional structure
38
Where are proteins made?
At the ribosome and then generally they fold into their active shape spontaneously
39
Where are the instructions needed for protein folding found?
Embedded in the amino acid sequence
40
Who proved that the instructions for protein folding were in the amino acid sequence?
Christian Afinsen, in a series of experiments that lead to a Nobel prize
41
What did Afinsen first do?
Took native ribonuclease and reduced the disulphide bonds causing the protein to denature
42
What did Afinsen observe?
The denatured protein was able to refold itself into native ribonucleas
43
What is protein folding directed largely by?
Its internal hydrophobic residues which form an internal core while hydrophobic residues are solvent exopsed
44
How his the sequence of protein folding described?
Not random
45
What is the first step in protein folding?
Formation of short secondary structure segments
46
What happens after formation of short secondary structure segments?
Nuclei or subdomains form
47
What happens after nuclei or subdomains form?
Subdomains come together to form a partly folded domain; a "molten globule" that can rearrange (tertiary structure still partly disordered)
48
What happens after a molten globule forms?
Final domain emerges small conformational adjustments to give final compact native structure
49
How are non covalent bonds individually?
Weak but in proteins, collectively they make a significant contribution to protein conformational stability
50
What do some proteins have?
Additional covalent bonds (disulphide bonds) which contribute to conformational stability
51
What is most likely the most important non covalent contributor to protein stability in aqueous solution?
Hydrophobic core
52
How do some proteins get assistance in folding?
By chaperones
53
What are the types of protein folding?
Chaperone independent, chaperone dependent and chaperonin dependent
54
What is an example of a chaperone?
Hsp70
55
What is an example of chaperonin?
GroEL-GroES
56
What % of proteins fold chaperone independent and dependent?
85%
57
What % of proteins fold chaperonin dependent?
15%
58
What can weakening of non covalent interactions do?
Lead to unfolding and loss of biological function (denaturation)
59
What may denaturation result from?
Change in pH, heating, detergents, organic solvents, urea and guanidium HCL
60
What forms of denaturation are irreversible?
Change in pH and heating
61
What forms of denaturation are reversible?
Urea and guanidium HCL
62
What can proteins in living organisms that are folded normally do?
Sometimes change their shape and become misfolded
63
What can some misfiled proteins do?
Can cause other proteins to change their shape as well, sometimes with disastrous consequences
64
What has been identified in the brain?
Three conditions due to a protein, PrP,that changes its shape and then form aggregates that cause brain damage: bovine spongiform encephalopathy (BSE), creutzfeld-jacob disease (CJD) and Kuru
65
What are the proteins that cause the brain disease called?
Prions or "proteins infectious agent"
66
What does the abnormal form of a prion protein, PrP do?
Induces the normal form of this protein to become misfolded
67
What transformation occurs due to prions?
alpha to beta
68
Is there treatment for the brain diseases?
No, they are always fatal
69
What other diseases are thought to be caused by protein misfiling or aggregation?
Alzheimers and Type 2 diabetes
70
What is involved in alzheimers an type 2 diabetes?
Not prions, an abnormally folded protein called amyloid is thought to contribute

BIOC192 (38 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions