Recent studies4-6 have demonstrated that the major molecular targets recognised by parietal cell autoantibodies are the á- and â-subunits of the gastric
proton pump (H/K-ATPase)7. The H/K-ATPase is the most
abundant membrane protein of the canalicular and tubovesicular membranes of parietal cells. It catalyses the countertransport of H+ and K+ in an electroneutral fashion at the expense of ATP and is thereby responsible for the acidification of the stomach.