Lecture 8 - Protein Folding III Flashcards Preview

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Flashcards in Lecture 8 - Protein Folding III Deck (19)
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1
Q

Describe the type of 2* structure associated with aggregated proteins?

A

Beta-sheets with cross linkage between them

2
Q

______ are proteins that consist of cross-linked beta sheets

A

Aggregates

3
Q

What are some possible causes of protein mis-folding/beta-sheet production?

A

Environmental damage/radiation/chemicals, etc.

4
Q

Outline the steps that form the amyloid plaque

A

Lack of chaperones -> “seeding” or “nucleation”
Nuclei begin to form fibrils (“stringlike” with beta-cross links)
Begin to form “deposits”

5
Q

Protein aggregation is characterized by formation of ______.

A

insoluble amyloid fibrils

6
Q

Amyloid fibrils are derived from what naturally occurring cell protein?

A

amyloid precursor proteins (APP)

7
Q

How are mis-folded proteins “marked” for degredation?

A

Through conjugation with uqiquitin, which marks it for removal by the proteosome.

8
Q

Destroys damaged organelles (normal function) or other mis-folded proteins (when then proteosome is saturated)

A

authphagosome

9
Q

Aside from seed polymerization, what other ways are proteins subject to aggregation?

A

Oxidative modification; phosphorylation; Ubiquitin like-SUMOylation; proteolytic cleavage

10
Q

(Large/small) protein aggregates are believed to be responsible for cellular damage in neurodegenerative disease.

A

small

11
Q

These contain a pocket that binds a metal ion; they then add the correct metal to proteins

A

metallochaperone

12
Q

What are the three main types of storage/transport metalloproteins?

A

e- carriers
metal managers
oxygen managers

13
Q

What are the three main types of enzymatic metalloproteins?

A

Hydroxylases
Oxidoreductases
Isomerases/synthases

14
Q

What is the structure of most “normal” proteins?

A

alpha-helix

15
Q

3 chars of infectious proteins

A
  • aggregates of a specific protein that is transmissible
  • proteins are resistant to dissolving
  • completely/largely derived from naturally occurring cell proteins
16
Q

Describe the characteristics of the “amorphorous aggregates” and why they are important to understanding disease.

A

Amorphorous aggregates have LESS E* and are MORE thermodynamically stable than native proteins; this causes them to “feed” into the pathway that produces amyloid fibrils

17
Q

The lack of what normal cellular mechanism is thought to promote “seeding” or “nucleation” of pro-amyloid fibril type protein structures

A

A lack of chaperone correction

18
Q

Zn, Pb, and Cd can all lead to _____ of protein folding

A

inhibition (heavy metal poisoning)

19
Q

Metal ions are required for the correct folding of almost ____ of all proteins.

A

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