Application

Antipain dihydrochloride from microbial source has been used in the preparation of adipocyte proteins for western blotting and in protease inhibitor cocktail for isolating nuclear extracts for gelshift analysis.

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 K_i = 1.4 µM

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.

Antipain dihydrochloride also inhibits the action of papain and cathespsin B.

General description

Chemical structure: peptide

Packaging

1, 5, 25, 100 mg in glass bottle

Preparation Note

Stock solutions in water or buffer stable for 1 week at 4 °C, 1 month at −20 °C.

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.