Question

Pepsin treatment produces the divalent F(ab')2 through splitting C-terminal to disulfide bond linking the 2 heavy chains, whereas papain treatment is required to __

Answer 1

Papain treatment is required to cleave an IgG molecule into two Fab fragments, which retain antigen binding capacity, and one Fc fragment, which does not bind antigen and is crystallizable.

Step-by-step explanation:

Papain treatment of an IgG molecule results in the cleaving of the molecule into two significant fragments. These are the Fab fragment, which contains the antigen binding capacity, and the Fc fragment, which does not bind to the antigen but can be crystallized. The enzyme papain, in the presence of cysteine, performs this function, whereby it cleaves the IgG molecule just above the disulfide bonds that link the heavy chains, without disrupting these bonds themselves. This process generates two identical Fab fragments and one Fc fragment, with the Fab fragments collectively making up two-thirds and the Fc fragment constituting one-third of the digested IgG molecule by weight.