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Updated: Jun 19, 2026
11:37
Analyzing Protein Dynamics Using Hydrogen Exchange Mass Spectrometry
Published on: November 29, 2013
THE INFLUENCE OF HYDROGEN ION CONCENTRATION ON THE INACTIVATION OF PEPSIN SOLUTIONS
1Laboratories of The Rockefeller Institute for Medical Research.
The Journal of General Physiology
|October 30, 2009
Summary
Pepsin enzyme stability is optimal at pH 5.0. Deviations to lower or higher pH rapidly increase pepsin
Area of Science:
- Biochemistry
- Enzymology
- Protein Chemistry
Background:
- Pepsin is a key digestive enzyme.
- Understanding pepsin's stability is crucial for its application.
Purpose of the Study:
- To determine the optimal pH for pepsin stability.
- To investigate the effects of pH on pepsin's rate of destruction.
Main Methods:
- Pepsin solutions were incubated at 38°C.
- Hydrogen ion concentration (pH) was systematically varied.
- Enzyme stability was assessed by measuring the rate of pepsin destruction.
Main Results:
- Pepsin exhibited maximum stability at a hydrogen ion concentration of approximately 10(-5) M (pH 5.0).
- Increasing or decreasing the pH from 5.0 led to a rapid increase in pepsin's rate of destruction.
- Enzyme purity and the type of acid anion did not significantly alter stability or the optimal pH range.
Conclusions:
- Pepsin has a narrow optimal pH range for stability around pH 5.0.
- The observed stability profile cannot be solely attributed to enzyme destruction by excessively weak or strong acidic conditions.
- Further research is needed to fully explain the optimal pH range for pepsin's protein digestion activity.
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