Molecular structural studies of effector functions of a mouse immunoglobulin G that lacks the entire C H1 domain: Small-angle X-ray scattering, nanosecond fluorescence depolarization and stable isotope-aided NMR analyses

Abstract

Molecular structural studies are reported of a short-chain mouse IgG2a antibody that lacks the entire C H1 domain. We have recently shown that (1) this short-chain antibody comprises two components in which the inter light-chain disulflde bridge does and does not exist, and (2) these two components are different in the constitutive complement-activating activity [Mizutani et al. (1993) J. Immunol. 150, 131–138]. Structures were compared for these two components on the basis of small-angle X-ray scattering, nanosecond fluorescence depolarization and isotope-aided NMR data. It has been discussed how the presence and absence of the inter light-chain disulfide bridges affect the complement-activating activity of the two components of the short-chain antibody.