Lecture 1 Flashcards
What does misfolding process trigger?
Self-association
What does self-association of proteins create?
Long amyloid plaques
What are proteins described as?
Living on a knife edge
Is the energy difference between folded and unfolded state huge?
No
What is the stability associated with a protein around?
5-15kcal/mol
What is one single hydrogen bond around?
2-5kcal/mol
How many hydrogen bonds does a medium sized protein have?
400-500 hydrogen bonds
What are Misfolding diseases a losing battle between?
Deposition and clearance
How many identified proteins are there that have caused different protein misfolding diseases?
24
What can diseases of amyloidosis be?
Local
Systemic
What is meant by local?
Restricted to a single organ e.g. brain
What is meant by systemic?
Protein aggregates can form across the whole body
What is half of your body mass?
A single aggregated protein
What are prions?
A group of conditions that affect the nervous system
Definition of prion
Collection of proteins which normally exist in our body but have misfolded and form insoluble aggregates
What does aggregation of proteins cause?
Death of cells
What is a PrP protein?
Normal protein found in the brain and under certain conditions e.g. mutation this protein will actually misfolding into protein PrPSC
What does PrP protein consist predominantly of?
Alpha helices
What does PrPSC have a higher proportion of?
Beta pleated sheets
What occurs during misfolding process?
Instead of forming all the alpha helices we form the beta pleated sheets
What does beta pleated sheets consist of?
Linear polymers that stack on top of one another - greater potential of bonding to other beta pleated sheets via non covalent bonds therefore forming aggregates
What are spongiform Encephalopathies prion disease?
Disease are fatal
No cure for them
What does spongiform refer to?
Characteristic appearance of infected brains which become filled with holes until they resemble sponges when examined under microscope
From early symptoms, when does the patient die?
Within a year
What are the neuropathology of Spongiform Encephalopathies prion disease?
Spongiform degradation of the brain
The brain shrinks and become spongy
Leaves holes in the white and grey matter of the brain
What are aggregation of proteins called?
Amyloid plaques
What is the property of protein plaque?
Resistant to proteolytic degradation