Monoclonal antibodies specific for the core protein of the β‐subunit of the gastric proton pump (H /K ATPase): An autoantigen targetted in pernicious anaemia

Abstract

The gastric H+/K+ ‐transporting adenosine triphosphatase (H+/K+ ATPase) (proton pump) consists of a catalytic α‐subunit and a recently proposed 60–90‐kDa glycoprotein β‐subunit. Using dog gastric membranes as the antigen, we have produced two murine monoclonal antibodies, 4F11 (IgG1) and 3A6 (IgA), which are specific for the 60–90‐kDa glycoprotein. The monoclonal antibodies (1) specifically stained the cytoplasm of unfixed and formalin‐fixed dog gastric parietal cells; (2) specifically reacted by ELISA with gastric tubulovesicular membranes; (3) recognised epitopes located on the luminal face of parietal cell tubulovesicular membranes, the site of the proton pump, by immunogold electron micr..