Step 1

Biochemistry 3

A 53-year-old man presents to the orthopedist’s office for evaluation of for recurrent symmetrical shoulder and wrist pain. He has not had any previous trauma and reports that he has not done any lifting since retiring from his sedentary job in air traffic control two years ago. He has a history of end-stage renal disease and has been on hemodialysis for 2 years. The orthopedist believes the pain to be due to a form of amyloidosis in which beta-2 microglobulin is deposited in the scapulohumeral joint as well as the radiocarpal joint.

Which of the following is the normal function of beta-2 microglobulin?

  • A) Make up a key component of MHC I
  • B) Mediate antibody binding to its specific antigen
  • C) Polymerize to form microfilaments that aid in cell movement and structure
  • D) Tag proteins for degradation via the proteasome


Kole Akula


Dr. Ted O'Connell