lecture 7 Flashcards
1
Q
define protein folding energy landscape theory
A
- Is a folding process
- Consider it like a funnel of free energies, the top represents unfolded states
- Polypeptides ‘fall down’ the funnel, as go down, less options for what can fold into + lower energy (more stable), until reach bottom
Note: lowest energy conformer = highest stability
2
Q
how do fibrous proteins (e.g. A keratin) fold?
A
○ Is structural + mechanically strong
○ Found in hair, nails etc.
Its structures promotes association fo helices to form coiled coils
refer to image
3
Q
how do globular proteins fold
A
○ Most polar residues face outside + itneract with solvent, while hydrohpbic residues face inside, itneract with each other
flexibility + allow for conformational changes
○ Core made of helices + sheets,
○ E.g. Ribonuclease
Catalyses the degradation of RNA into smaller components
4
Q
describe IUPs
A
- Proteins that exist/function normally in a PARTIALLY unfolded state
- Essential for cellular function
- No structure + high flexibility, however become structured when bind to target proteins
- Characterised by abundance of polar + lack of hydrophilic resiudes
- Some IUPs can change shape to bind to multiple protein partners, so can be involved in multiple signalling + regulatory pathways
E.g. Tumour suppressors
5
Q
why is protein folding/structure important?
A
- For predicting 3D structure from the sequence
- Determining biological function
- Understanding + treating protein misfolding diseases
- Production of recombinant proteins in pharmaceutical industry + biotechnology
6
Q
name 4 protein misfolding diseases
A
- Alzheimer’s
- Parkinson’s
- Huntington’s
- Prion protein disease
-mad cow disease- not in humans
7
Q
describe prion protein disease
A
- Normal prion protein (PrPc) found in nerve cells
- If prion changes its conformation from normal to disease causing- scrapie protein (PePSc), gets into nervous system, infects other normal prions, causes nerve cell death, leaving holes behind
