Pepsin
Pepsin — An aspartic protease in gastric juice that cleaves peptide bonds, particularly at hydrophobic residues, used in peptide mapping protocols.
What Is Pepsin?
Pepsin is an aspartic endoprotease active at pH 1.5-4 in the stomach that cleaves peptide bonds preferentially at hydrophobic residues (Phe, Trp, Tyr, Leu). Pepsin resistance is a critical benchmark for orally delivered peptides and is tested by incubating peptides at pH 2 with pepsin.
Applications
- Stability testing: Simulated gastric fluid (SGF: pH 1.2, pepsin) challenge for oral peptide candidates
- HDX-MS: On-ice pepsin digestion for hydrogen-deuterium exchange MS (works at low pH)
- Antibody fragmentation: Pepsin generates F(ab')2 fragments below the hinge region
Frequently Asked Questions
What is Pepsin?
An aspartic protease in gastric juice that cleaves peptide bonds, particularly at hydrophobic residues, used in peptide mapping protocols.
Why is Pepsin important in peptide research?
Pepsin is a fundamental concept in biochemistry as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.