Reverse immunoaffinity chromatography: Application to the purification of the 60- to 90-kDa gastric parietal cell autoantigen associated with autoimmune gastritis

Abstract

Previous attempts to purify autoantigens by affinity chromatography using the total IgG from autoantibody-positive sera have not been very successful. We describe here a novel method using parietal cell autoantibodies, isolated on a crude autoantigen immunoabsorbent column, for the purification of the 60- to 90-kDa gastric parietal cell antigen targeted in autoimmune gastritis. The 60- to 90-kDa parietal cell antigen was first enriched 2.5-fold from a 0.5% Triton X-100 extract of total pig gastric mucosal membranes by DEAE-Sepharose 4B chromatography. The fraction containing the 60- to 90-kDa antigen was directly coupled to CNBr-activated Sepharose 4B to produce an immunoadsorbent column for..