gastric H+/K+ ATPase (H+ transporting ATPase, K+ transporting ATPase, proton pump)

Function

• catalyzes hydrolysis of ATP coupled with exchange of H+ & K+ ions across the plasma membrane
• responsible for acid production in the stomach
• secretes HCl; 900 fold H+ gradient obtained via hydrolysis of ATP

Inhibition:

• proton pump inhibitors (direct inhibition)
• H2 receptor antagonists (indirect inhibition)

ATP + H2O + H+(in) + K+(out)
            <-->
ADP + phosphate + H+(out) + K+(in)

Structure

• composed of two subunits: alpha (catalytic) & beta

More general terms

• E1-E2 ATPase or P-type ATPase
• regulatory molecule
• plasma membrane protein
• multisubunit protein

Additional terms

• proton pump inhibitor