Papain digestion of an IgG molecule results in which of the following?

Papain digestion of an IgG molecule results in which of the following?

• A. 2 Fab' and 1 Fc' fragment
• B. F(ab')2 and 1 Fc' fragment
• C. 2 Fab and 2 Fc fragments
• D. 2 Fab and 1 Fc fragment

Answer: (D)

Papain cuts IgG in the hinge region, cleaving above the disulfide bonds that connect the heavy chains. This splits the antibody into two separate Fab fragments, each containing one antigen-binding site, and one Fc fragment that contains the constant region responsible for effector functions. The two Fab pieces are not linked to each other like the F(ab')2 fragment produced by pepsin digestion; instead, they exist as individual Fab fragments alongside a single Fc fragment. So, the digestion yields two Fab fragments and one Fc fragment.

Papain cuts IgG in the hinge region, cleaving above the disulfide bonds that connect the heavy chains. This splits the antibody into two separate Fab fragments, each containing one antigen-binding site, and one Fc fragment that contains the constant region responsible for effector functions. The two Fab pieces are not linked to each other like the F(ab')2 fragment produced by pepsin digestion; instead, they exist as individual Fab fragments alongside a single Fc fragment. So, the digestion yields two Fab fragments and one Fc fragment.