Role of inter-heavy and light chain disulfide bonds in the effector functions of human immunoglobulin IgG1.

The role of inter-heavy and light chain disulfide bonds in the effector functions of human IgG1 was investigated. This was accomplished by mutating appropriate sites in IgG1 such that the disulfide bond pattern now resembled that of IgG4. The effector functions of the mutant antibody were then compared to native IgG1 and IgG4. The antibody-dependent cell cytotoxicity activity was completely abolished in the mutant and the complement-dependent cytotoxicity assay was reduced fifteen-fold. The results suggest that the inter-heavy and light chain disulfide bond pattern of an antibody molecule play a role in its effector functions.