HealthMap

Pepsinogen Activation and Gastric Secretion

• Chief cells secrete the inactive enzyme precursor pepsinogen into the gastric lumen.
• Hydrochloric acid (HCl), secreted by parietal cells, is strictly required to convert inactive pepsinogen into active pepsin.
• The acidic environment (low pH) causes a conformational change in pepsinogen, resulting in the cleavage of its own inhibitory peptide fragment.
• Once active pepsin is formed, it can also catalyze the activation of other pepsinogen molecules in a process known as autocatalysis.
• Without sufficient stomach acidity, protein digestion is severely impaired because this biochemical conversion cannot take place.