Hydrogen Potassium Adenosine Triphosphatase (H+/K+-ATPase)

Hydrogen potassium adenosine triphosphatase, commonly referred to as H+/K+ ATPase or the gastric proton pump, is a membrane-bound enzyme primarily responsible for the acidification of the stomach. It achieves this by exchanging intracellular protons (H+) for extracellular potassium ions (K+) in gastric parietal cells. It is composed of two subunits: α-subunit (~100 kDa), which contains ten transmembrane segments housing catalytic and ion-binding domains, and β-subunit (~30 kDa) with a single transmembrane segment which is heavily glycosylated extracellular domain important for assembly, maturation, sorting, and trafficking. H+/K+-ATPase is targeted by proton pump inhibitors (PPIs), a major class of drugs used in treating acid-related gastrointestinal diseases.

Other names

Gastric proton pump

Irreversible inhibition of H+/K+-ATPase activity by PPIs