Proton Pump inhibitor (PPI) is a ATPase that catalyzes the transfer of proton (H+) from lumen to extra cellular vicinity.

1. Proton Pump and its inhibitor
Ahtesham Hanifi
I200602

2. Proton Pump
• Multisubunit ATPase that catalyzes the translocation of protons from the cytoplasm
into the lumen of a variety of intracellular organelles, including synaptic vesicles (
Fundamental Neurosciences ( 4th edition ) 2013 ).
• Proton Pump belongs to P-type subfamily of ATPase.
• Common pathway for secretion of acids.
Cells 2022, 11, 4052.
https://doi.org/10.
3390/cells11244052

3. Mechanism of Proton Pump action
• Secretion of proton ( H+ ) from cytosol into lumen is depends on availability of CO2.
• As CO2 enters cytosol, give rise to carbonic acid ( H2CO3 ) with water in presence of
enzyme carbonic anhydrase.
• Carbonic acid ( H2CO3 ) is unstable so its breaks into components: H+ and HCO3
- .
• H+ is now pumped out from cytosol to lumen through proton pump on expanses of
an ATP.

4. https://www.sciencedir
ect.com/science/article
/pii/B9780123858702000
07X

5. Proton pump in plant system
https://biorender.com

6. Proton Pump inhibitor ( PPI )
• Proton pump inhibitors ( PPIs ) are class of drugs that blocks proton pump in
oxyntic cells . e.g. Omeprazole and Iansoprazol.
• Omeprazole is a powerful proton pump inhibitors.
•
Lifevision-2 ( A division of
Lifevision Healthcare)
Pharmacotherapy 2003;23(10 Pt
2):74S–80S

7. Mechanism of action of PPIs
• Once PPIs binds to proton pump channel, it gets converted into sulfenic acid and
then sulfenamide.
• This sulfenamide inactivates an enzyme H+/K+ ATPase and prevents proton ( H+ )
secretion.
Pharmacotherapy 2003;23(10
Pt 2):74S–80S

8. • Advantage : PPIs are reported to be effective to prevent recurrence of reflux symptoms
and esophageal erosions/ulcers.
• Disadvantage: Headache, Rash, Dizziness, Abdominal pain and several gastrointestinal
medical conditions.

9. Thank you