Protein Folding 2 Flashcards
What other structure does tertiary structure include?
Secondary structure
Protein folding is a highly cooperative process true or false?
True
Proteins can be denatured. True or false?
True
Protein folding is not a all or none process. True or false?
False- protein folding is an all or none process.
What happens when there is partial loss of folding?
The protein is destabilized and ruins the rest of the structure.
What conditions and chemicals denature proteins?
Heat, pH extremes, agitation
Chemicals-
Detergents
Chaotrophic agents (urea, guamidine hydrochloride)
Organic solvents ( TCA)
How can you test for protein denaturation?
Turbidity- cloudiness
Circular Dichroism (CD)- + - which way the protein refracts light.
Fluorescence- detecting presence of aromatic AA
Tryptophan, tyrosine, and phenylalanine.
UV absorption- peptide bonds absorb UV light at 200 nm and AA 80nm. Helps determine how many peptide bonds are present
Biological activity- If enzymatic activity isn’t what you’d expect proteins could be denatured.
What is the purpose of accessory proteins?
They help to mature and direct the brand new proteins.
What does the PDI accessory protein help with?
It tells the protein where to go and helps it find its partner.
What does PPI do?
Positions amino acids as either cis or trans and makes the right sulfide bridges between cysteines.
What is the purpose of HSP 70 (HSP 40)?
ATP driven and reverses misfolds.
What are chaperonins and give examples
HSP 90- helps signal transduction proteins
Nucleoplasmins- helps the transcription factors
Small HSP
How many groups of chaperones are there?
Two, one for eukaryotes and another for mitochondria and bacteria.
What do the Chou-Fasman Method and Kytle-Dootlittel hydropathy plots tell you?
They help to determine secondary structure and which amino acids are hydrophilic or hydrophobic.
