Q. Which one of the combinations of the following statements is true about antibody structure?
P. Limited proteolysis of rabbit IgG with the enzyme pepsin generates two antigen-binding regions (Fab) and an Fc fragment
Q. Limited proteolysis of rabbit IgG with the enzyme papain generates a single bivalent antigen-binding region F(ab¢)2 and peptide fragments
R. The Fc fragment of IgG can self-associate and crystallize into a lattice
S. The F(ab¢)2 fragment of IgG is composed of both light and heavy chains
(A) P and Q only
(B) P and R only
(C) R and S only
(D) Q and S only
Ans: R and S only