ANTIPAIN DIHYDROCHLORIDE

General description

Antipain is a protease inhibitor isolated from actinomycetes. It inhibits thrombokinase and blood coagulation.

Application

Concentrations for 50% inhibition (μg/ml):
papain, 0.16
trypsin, 0.26
cathepsin A, 1.19
cathepsin B, 0.59
cathepsin D, 125
plasmin, >93
chymotrypsin and pepsin, >250
It 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.

Formula variant

Formula: C₂₇H₄₄N₁₀O₆ x 2 HCl

Preparation Note

Working concentration: 50 μg/ml

Working solution: Soluble in water, methanol, or DMSO to 20 mg/ml. Sparingly soluble in ethanol, propanol, or butanol. Insoluble in benzene, chloroform (CHCl₃), hexane, or petroleum and ethyl ethers.
Storage conditions (working solution): -15 to -25 °C
Dilute solutions should be stored frozen in aliquots at -15 to -25 °C. Growth of microorganisms and repeated freezing should be avoided. Stable for approximately one month.

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.

Reconstitution

Soluble in water, methanol, or DMSO to 20 mg/ml. Sparingly soluble in ethanol, propanol, or butanol. Insoluble in benzene, chloroform (CHCl₃), hexane, or petroleum and ethyl ethers. Dilute solutions should be stored frozen in aliquots at -15 to -25 °C. Stable for approximately one month.
CAUTION: DMSO (Dimethyl sulfoxide) will permeate the skin, carrying solubilized protease inhibitors. Always wear appropriate protection for eyes, skin, etc.

Other Notes

For life science research only. Not for use in diagnostic procedures.