Journal of Neurogastroenterology and Motility : eISSN 2093-0887 / pISSN 2093-0879

Download original image
Fig. 2. Comparison of mechanisms of action of lansoprazole (conventional proton pump inhibitor) and vonoprazan (potassium-competitive acid blocker). Hydrogen potassium (H+, K+)-ATPases are located in tubulovesicles in quiescent phase and appear on the apical membrane of secretory canaliculus in the active phase, which occurs after a meal. Lansoprazole converts to its active form in the secretory canaliculus, though it degrades soon after (X). The active form of lansoprazole covalently binds to H+, K+-ATPase (proton pump). Vonoprazan stably accumulates in the acidic secretory canaliculus and non-covalently binds to H+, K+-ATPase with very a very slow dissociation rate and can inhibit newly exposed H+, K+-ATPase for a long time.
Journal of Neurogastroenterology and Motility 2018;24:334~344 https://doi.org/10.5056/jnm18029
© J Neurogastroenterol Motil