A novel catalysis by porcine pepsin in debranching guar galactomannan.
Carbohydrate polymers
confidence
Key findings
Porcine pepsin catalyzes debranching of guar galactomannan via Asp(138), showing non-specific glycosidic catalysis; no clinical/biological endpoints.
View source on PubMed (PMID 24507326) ↗
- Population
- In vitro (porcine pepsin and guar galactomannan)
- Blinding
- not_reported
- Controls
- not_reported
- Drug class
- digestive enzyme blend
Full abstract
Pepsin (porcine stomach mucosa, E.C. 3.4.23.1), an acid protease catalyzes the hydrolysis (debranching) of guar galactomannan (GG), a co-polymer of mannose and galactose residues thereby showing its non-specific catalysis towards glycosidic substrates. Use of non-specific inhibitors, chemical modification agents and peptide mapping of native and GG--bound pepsin upon proteolytic digestion with Staphylococcus aureus V8 protease revealed the involvement of Asp(138) residue in the catalysis, which was confirmed by computational modelling studies. Here we show a novel mode of catalysis (other than proteolysis) by porcine pepsin with a different active site residue.