Immunology

Question 1

What is the structure of MHC I?

Answer 1

An alpha chain with three domains, which curves over and has one membrane anchor,
There is also a beta 2 microglobulin molecule which allows for stability
This molecule is capped, causing a limitation in the length of the polypeptide that can be displayed

Question 2

What is the structure of MHC II?

Answer 2

Has both an alpha and beta chains with each having a membrane anchor
The variability is provided by the beta chain
This protein is uncapped so long peptides can be displayed

Question 3

What is the structure of the light chains of immunoglobulins?

Answer 3

There are two chains, the kappa and lambda chain which have no functional difference, they are assembled from V and J segments combined with a constant region.
Each contain 3 CDR loops which provide variability, the V segment provides additional variability through the high mutation rate of RAG recombinase

Question 4

What is the structure of the heavy chains of immunoglobulins?

Answer 4

Composed of a V, J and D regions where different combinations cause the variability
Several constant regions which code for the different isotypes of Ig molecules

Question 5

What is the structure of the T cell receptor?

Answer 5

Similar to Ig structure, but less specific
made of alpha and beta chains, both of which contain a constant region closest to the cell and a vairable region above it

Question 6

What is the structure of Toll-like receptors?

Answer 6

Trans-membrane proteins with leucine rich repeat extracellular domain which binds antigens