Aspergillopepsin I (PEP1)

Aspergillopepsin I is a major acid protease secreted by the fungus Aspergillus oryzae, an organism widely utilized in the food industry for fermentation processes [1, 11]. This enzyme belongs to the aspartic protease family (EC 3.4.23.18) and is characterized by its ability to function effectively in acidic environments, similar to human pepsin [3, 5]. It plays a critical role in the degradation of complex proteins into smaller peptides and amino acids, and it is also capable of activating zymogens such as trypsinogen and chymotrypsinogen [10, 12]. Therapeutically, Aspergillopepsin I is employed as a digestive aid in enzyme replacement therapies for individuals with gastric insufficiency or protein malabsorption [8, 13]. In drug discovery, it serves as a significant model for studying aspartic protease inhibitors, such as Pepstatin A, which are relevant for developing treatments against pathogenic fungi like Aspergillus fumigatus [6, 18]. The interaction between this protease and its inhibitors provides valuable insights into the structural biology of fungal virulence factors and the development of novel antifungal agents [17, 19].

Other names

Aspergillopepsin-1Acid protease A2Aspartic protease pepAAspergillopeptidase AAspergillus oryzae acid protease

Aspergillopepsin I is an aspartic protease that utilizes two conserved aspartic acid residues in its active site to catalyze the hydrolysis of peptide bonds [3, 7]. The mechanism involves the activation of a water molecule by the aspartates, which then performs a nucleophilic attack on the carbonyl carbon of the scissile peptide bond [10]. It shows broad substrate specificity with a preference for hydrophobic residues at the P1 and P1' positions [5, 12].