Protein Folding III Flashcards
What do proteasome do?
Give the kiss of death. Eliminates the misfolded unrescuable proteins
Quality-control mechanisms detect what types of proteins?
Incorrectly folded proteins
Why are proteins misfolded?
It is dependent on the energy.
What does the Energy landscape govern?
Protein folding and aggregate formation. Light blue indicates the intramolecular contact. Intermolecular contact is the blue-one misfolded protein excapes from the chaperon treatments and interacts with the other semi misfolded proteins and the energy levels goes down.
What is the native state in thermodynamics terms?
Native state is the thermodynamically preferred structure
What state is not thermodynamically preferred in energy landscape?
Amyloid fibrils that forms at the lowest energy level
Amyloid structure of the aggregated protein differs from normal proteins in what way?
Normal proteins contain more alpha helix structure and little beta strands. Amyloid has more beta structures.
How does the amyloid progress to amyloid plaques?
Seeding (nucleation) - amyloid proteins form a seed
Fibril formation - Seed continues to grow and forms a fibril. Toxic form.
Deposit - Body detects the toxic fibril but proteasome cannot remove them so they are deposited. (contained) so a cocoon is formed (lewy body)
What happens to larger aggregates in the cell body
Contained in Lewy bodies to protect the cell from apoptosis
What damage do small aggregates cause?
Cause cell membrane damage
Where are amyloid fibrils deposited?
Heart, liver, spleen, and brain
What is the structure of amyloid fibril?
Cross beta structure with beta strands perpendicular to backbone structure
What is expended when misfolded proteins are taken to the proteasome?
ATP
What is important in metalloprotein folding
Metals
What are the two types of metalloproteins?
Transport and storage proteins
enzyme proteins
