Proteins in Membranes

Question 1

what are the 2 main properties of integral membrane proteins

Answer 1

1. totally embedded transmembrane proteins

2. lipid anchor embedded within outer/inner of membrane

Question 2

what are the 2 main properties of peripheral membrane proteins

Answer 2

1. non-covalently(reversibly) bound to -ve membrane patches

2. presence of adaptor proteins ex. kinases, bound to cytoplasmic domain of receptor adhesion molecules

Question 3

what are PI3, 4, 5P

Answer 3

negatively charged patches of membrane which peripheral membrane proteins are attached to

Question 4

Topology and AA composition of transmembrane proteins can be predicted from the gene sequence of the protein, using

Answer 4

the Kyle-Doolittle plot

Question 5

The Kyle-Doolittle plot

Answer 5

uses a database of known protein structures for prediction of alpha helices, beta sheets and turns

Question 6

what are the turns of the transmembrane domain stabilised by?

Answer 6

H bonds between amide turns on adjacent turns

Question 7

what is a further test for topology of transmembrane domains?

Answer 7

using an antibody to see whether it will bind