The unfolding/denaturation of immunogammaglobulin of isotype 2b and its Fab and Fc fragments

The unfolding and further denaturation of IgG and its F-ab and F-c fragments were studied both on a macroscopic and molecular level, using differential scanning calorimetry and circular dichroism spectroscopy, respectively. It was shown that the structural integrity of the F-ab and F-c units was retained after fragmentation of the IgG. The F-ab fragment denatured at similar to 61 degrees C and the F-c fragment at 71 degrees C. The structural transitions observed in the whole IgG is the sum effect of those determined for the isolated F-ab and F-c fragments.