Figure 7-38

Disulfide Bridges:
Click on structure and drag to rotate. Click on figure to reset.

X-ray structure of a murine antibody against canine lymphoma (a type of cancer against which this antibody is therapeutically useful). The antibody is shown in ribbon form with its two heavy chains gold and cyan and its two light chains both magenta. Its two identical nonasaccharide chains, which are sandwiched between the protein's CH2 domains, are drawn in space-filling form with C green, N blue, and O red. Click on the Show "Disulfide Bridges" button to highlight in orange the disulfide bridges that stabilize the tertiary and quaternary structures of the antibody. Click on the Show "Antigen-Combining Sites" button to highlight in green the antigen-combining sites, which are located at the ends of the two approximately horizontal Fab arms. Note that the antibody lacks twofold symmetry due to the flexibility of the peptide links joining the constant and variable regions of its heavy chains. [Based on an X-ray structure by Alexander McPherson, University of California at Irvine. PDBid 1IGT.]