A novel catalysis by porcine pepsin in debranching guar galactomannan

AbstractBackground (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. s and conclusions 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 Asp138 residue in the catalysis, which was confirmed by computational modelling studies. l significance e show a novel mode of catalysis (other than proteolysis) by porcine pepsin with a different active site residue.