Physiochemical features of monoclonal idiotype-anti-idiotype complexes: importance of inter-chain disulfides for size distribution patterns and molecular geometries.

Cyclic tetramers represent the preferentially formed complexes of a murine monoclonal idiotype-anti-idiotype (Id-anti-Id) system consisting of IgG antibodies or (Fab')2 fragments at micromolar concentrations. The cleavage of inter-chain disulfides of both Id and anti-Id caused the predominant generation of cyclic dimers at the expense of larger aggregates, suggesting with regard to already published data that the hinge located interheavy-chain disulfides are essential for the strain.