DD - Protein Structure (2) Flashcards
What is the tertiary structure of a protein?
The final 3D structure of a polypeptide chain
What bonds are involved in the tertiary structure?
Hydrophobic interactions
Hydrogen bonds
van der Waal interactions
Ionic bonds
Covalent bonds
Disulphide bonds
How was the Anfinsen Experiment on Ribonuclease conducted?
Anfinsen transfomed the native ribonuclease to the unfolded state and then back into the native state, with the addition and removal of urea
What did Anfinsens experiment show?
The primary structure has the folding pattern for the protein
What was Levinthal’s conclusion?
Protein folding has a strong driving force behind it
What interactions are thought to be the prime driving force for protein folding?
Hydrophobic Interactions (Hydrophobic Collapse)
What type of amino acids do hydrophobic interactions form?
Aromatic (Disrupted by heat)
What type of amino acids form hydrogen bonds?
Polar, non-charged residues (Disrupted by heat, denaturing agents and water)
What type of amino acids form Electrostatic bonds?
Between charged residues acidic and basic (disrupted by heat, pH and salt)
What determines the charge on a protein?
- pH
- The number and type of each amino acid residues with ionisable side chains
What are some properties of van der Waal interactions and how are they disrupted?
- Are relatively weak and so have very short range effects
- Disrupted by heat and denaturing agents
What is the protein folding funnel?
A series of increasingly restricted movements until a low-energy minimum is reached
What is a protein domain?
- An area of protein that folds independentely
- Can often perform a specific function
What does protein misfolding result in?
The aggregation of proteins
