Week 5 Bollough Lecture 3

Question 1

What makes a simple integral membrane protein?

Answer 1

A hydrophilic core and a hydrophobic outer surface

Question 2

what sorts of amino acids would you expect on the outer face of an integral membrane protein?
a) can you give some examples of such amino acids?

Answer 2

Hydrophobic amino acids

a) Glycine, proline, phenylalanine, alanine, isoleucine, leucine and valine

Question 3

what sorts of amino acids would you expect to be lining the pore of an integral membrane protein?
a) can you give some examples of such amino acids?

Answer 3

Hydrophilic amino acids

a) Serine, Threonine, Asparagine, glutamine, cystine, aspartate, glutamate arginine and histidine

Question 4

What is the structure of a porin?

Answer 4

Formed from beta-strands

a) Each strand is hydrogen bonded to its neighbour in an antiparallel arrangement, forming a single β sheet.
b) The β sheet curls up to form a hollow cylinder forming a pore, or channel, in the membrane.