Effect of Pepstatin on Acid Proteases

Abstract

Pepstatin is shown to be a specific inhibitor of acid proteases. It also inhibits humangastricsin, but the effect is weaker than against humanpepsin. The content of pepsin and gastricsin in gastric juice of stomach ulcer patients is described and the pepstatin which remains in gastric juice collected at 60 minutes after its administration is also determined. These results and those obtained by the direct measurements of the peptic activity of the gastric juice indicate that a sufficient amount of pepstatin to inhibit pepsin remains in the

The selectivity of action of the aspartic-proteinase inhibitor IA3 from yeast (Saccharomyces cerevisiae)

“…Other aspartic-proteinase inhibitors (naturally occurring and synthetic), although displaying preferences for individual (types of) enzyme(s), nevertheless do show some inhibitory efficacy towards many of the enzymes. For example, within the group of pepstatins (Aoyagi et al, 1971;Umezawa & Aoyagi, 1977), which contain the unusual amino acid statine as a dipeptide analogue (Holladay et al, 1985), isovalerylpepstatin has Ki values towards (various) pepsin(s) and cathepsin D of approx. 10-10 M (Rich & Bernatowicz, 1982; Knight & Barrett, 1976), but values of 3 x 10-8 M and lower against calf chymosin and other enzymes (Valler et al, 1985a;Holdsworth et al, 1985).…”

Treatment of cashew extracts with Aspergillopepsin reduces IgE binding to cashew allergens

“…Aspergillopepsins require aspartic and glutamic acid residues for catalytic activity [38,39] and two forms of ASP are generated ASP I and ASP II [40,41]. ASP I (GI 134081775) is a pepsin-type aspartic proteinase with a predicted molecular weight of 41 kDa, that is active within a range of pH 2.0 to 4.0, and can be inhibited by pepstatin [26,42,43]. In contrast, ASP II (GI 134054586) is a non-pepsin-type acid proteinase, with a predicted molecular weight of 30 kDa, that is active in a pH range between pH 2.0 to 3.0 and is resistant to pepsin-type aspartic proteinases inhibitors such as pepstatin [42,44,45].…”

“…ASP I (GI 134081775) is a pepsin-type aspartic proteinase with a predicted molecular weight of 41 kDa, that is active within a range of pH 2.0 to 4.0, and can be inhibited by pepstatin [26,42,43]. In contrast, ASP II (GI 134054586) is a non-pepsin-type acid proteinase, with a predicted molecular weight of 30 kDa, that is active in a pH range between pH 2.0 to 3.0 and is resistant to pepsin-type aspartic proteinases inhibitors such as pepstatin [42,44,45]. Despite the differences in size and inhibitor sensitivity, both ASP enzymes can be irreversibly inactivated above pH 6.0 [46].…”

Enzymatic Changes in Pancreas and Liver of the KK Mouse As an Animal Model of Diabetes Mellitus

“…Trichloroacetic acid (1 ml of 9% solution) was added to stop the reaction, and the mixture was kept 1 h at room temperature. The supernatant was withdrawn by centrifugation (2,000 x g, 5 min), and the absorbance at 280 nm determined [9,15]. For the glycosidase assays, 0.1 ml of 25 mM p-nitrophenyl derivatives were used as the substrate.…”