Antibodies recognizing different domains of the polymeric immunoglobulin receptor.

摘要: The receptor responsible for the transepithelial transport of IgA dimer antibodies is a transmembrane glycoprotein known as membrane secretory component (SCm). During transport, anchoring domain cleaved and ectoplasmic (SCs) remains tightly bound to in exosecretions. We have produced monoclonal with distinct specificities against both cytoplasmic epitopes rabbit SCm. One antibody (anti-SC303) reacted SCm free SCs but not (SIgA). Therefore, it recognized an epitope close binding site. other (anti-SC166), which was unable react SCs, 15-kDa extension membrane-spanning receptor. A polyclonal (GaR-SC), raised goat milk subpopulation by anti-SC303 addition also covalently sIgA. three cross-reacted rat demonstrate ability anti-SC166 immunoadsorb subcellular organelles result orientation its epitope. Our data indicate that there are functional differences between high- low-molecular-weight families SC terms binding.