Application Concentrations for 50% inhibition (μg/ml): papain, 0.16trypsin, 0.26cathepsin A, 1.19cathepsin B, 0.59cathepsin D, 125plasmin, >93chymotrypsin and pepsin, >250It also has been reported to inhibit calpain I, (porcine) with Ki = 1.4 μM Preparation Note Solubility testing at 50 mg/ml in water yields a clear to slightly hazy yellow solution. It is reportedly soluble in methanol, water, and DMSO; less soluble in ethanol, butanol, and propanol; insoluble in benzene, hexane, and chloroform.8 A stock solution in water or buffer is stable for about a month at -20 °C.Dilute solutions should be stored on ice and kept for only a day because of the terminal aldehyde, which is subject to oxidation and racemization. Stock solutions in water or buffer stable for 1 week at 4 °C, 1 month at -20 °C. Biochem/physiol Actions Reversible inhibitor of serine/cysteine proteases and some trypsin-like serine proteases. Its action resembles leupeptin; however, its plasmin inhibition is less and its cathepsin A inhibition is more than that observed with leupeptin. Chronic administration of antipain can reduce the frequency of chemically induced transformation in BALB/c-/3T3 cells.1 |