Week 5 Bollough Lecture 6 Flashcards
What is a hydropathy?
how much the amino acids dislikes being transferred from a hydrophilic region to water
Do amino acids have similar hydropathies?
No, they have different hydropathies.
What does the transfer free energy tell us about an amino acid?
Free energies for the transfer of an amino acid residue in an a-helix from the membrane interior to water
What does a hydropathy plot predict?
can predict membrane spanning alpha helices
What are the features of a hydrocarbon core membrane?
Usually 30 Armstrongs wide, and 20 residues (number of amino acids needed to span the membrane)
What is the function of glyphorin A?
a) How does the sequence determine function?
b) Why does it need to be membrane anchored?
Detects MN blood groups
a) Has 3 segments,
i) first is 62 aa long which is exposed out of cell. High levels of serine and threonine.
ii) Middle is hydrophobic alpha helix
iii) C-terminal region contains lots of acidic and basic amino acids
b) This is to allow it to interact with the proline on the outside of the cell
Why would hydropathy plots not work for predicting beta barrel membrane proteins?
Not long enough
a) And because the amino acids alternate between hydrophilic and hydrophobic
