Questions on MHC Structure  Most of these questions can be
answered by referring to the images at It will also be helpful
to refer to the appropriate chapter of a textbook of immunology.
These questions will help you focus your tour of MHC structure.
It is recommended that you print this page and write your
answers. Have your answers checked by your instructor.      MHC
Class I Extracellular Domains    1. How many polypeptide chains
make up MHC class I?    2. Which chains are invariant? Which
show allelic variability?    3. Which domains have
immunoglobulin-like structure?    4. Does CD8 bind to a domain
of high or low variability? What would you predict about the
variability of the amino acids which bind CD8?    5. Which end
of the molecule is anchored to the cell membrane, and which end
binds to the TCR?      Cleft of MHC Class I    6. Which regions
of MHC contact the antigenic peptide?    7. What secondary
structures make up the walls ("lips") and the floor of the
cleft?    8. Are the ends of the peptide