7 Protein Structure Flashcards
in a water soluble protein, where would you find hydrophobic interactions?
on the inside of the protein
what do destabilizing amino acid mutations do to the protein?
cause it to fold incorrectly
what happens if a protein is not folded?
they aggregate and are improperly trafficked
what is the specific activity of a protein?
amount of activity per amount of protein
what amino acid is strongly disfavored in alpha ehlices?
proline
what charge of amino acids are disfavored for alpha helices?
same charges next to each other
T/F alpha helices can be amphipathic? what is amphipathic?
- True
- a molecule that has both hydrophobic and hydrophilic parts
T/F prolines can be incorporated into beta sheats?
Tru
what orientation are adjacent side chains in in beta sheets
-opposite (C and N terminus are flipped with every chain)
what connects strands of beta sheets?
hydrogen bonds
what is a primary characteristic of glycine?
it is small
what is a key feature of tyrosine and tryptophan that allows us to measure proteins?
they both absorb UV light
how many domains does the CFTR have and what are their characteristics?
- 5 domains
- 2 transmembrane
- 2 nucleotide binding
- 1 R domain
how is the CFTR protein activated and what does this allow for?
- phosphorylation of the R domain
- ATP binding and hydrolysis by NBD domains
- allows passage of chloride ions through the plasma membrane
what is kalydeco used for?
to treat patients with the rare G551D mutation that causes CF (mutation in a codon that typically codes for a glycine)
what does a glycine residue allow for in protein structure?
allows for sharp bends in the protein so that other amino acids can interact with each other
in what situation is a desmosine cross link important and what amino acid allows for this to happen?
- important in elastin in order to give tissues an elastic property
- formed between two lysine residues
keratin contains what protein structure in order to induce strength and shape?
alpha helices
fibrous proteins are soluble in water, T/F
false
elastin contains what type of cross linking?
desmosine, facilitated by lysine residues
what is the protein of hair, nails , and skin , and what is the shape of the protein?
keratin
-it is very helical
conceptually what is the pka?
the ph at which you have 50% of the conjugate acid and 50% in conjugate base form: this is when it can best absorb changes in pH
what is a major buffer inside the blood?
phosphate and bicarbonate
what is the carbonic acid equillibrium in the blood
CO2 + H2O - H2CO3 - H + HCO3
if the pH is off, what might happen to some of the side chains?
the charge on them might be wrong, leading to dysfunction
hows is pH important to aspirin?
The pH will dictate if aspirin is a charge molecule or not. If aspirin is charged, then it will not be able to diffuse through cell membranes and have its effect.
what is the isoelectric point?
the pH at which a molecule is electrically neutral
when does maximum buffering occur?
when there is an equal amount of conjugate acid and base
three major buffers in the body
- phosphate
- bicarbonate
- proteins
