Application

The protease inhibitor cocktail improves the yields of intact proteins by adding inhibitors to enzymes that modify proteins present in cell extracts. This product has been optimized and tested for bacterial cell use, with broad specificity against serine, cysteine, and aspartic proteases, metalloproteases, and aminopeptidases.

Biochem/physiol Actions

This mixture contains individual components, including AEBSF at 23 mM, EDTA at 100 mM, Bestatin at 2 mM, Pepstatin A at 0.3 mM, and E-64 at 0.3 mM. AEBSF acts to inhibit serine proteases, including trypsin, chymotrypsin, and plasmin amongst others. Bestatin inhibits aminpeptidases. E-64 acts against cystein proteases. Pepstatin A inhibits acid proteases. EDTA is an inhibitor of metalloproteases.

Caution

The lyophilized powder is stable for at least 2 years when stored unopened at -20°C. It is also supplied with a vial of DMSO. A prepared solution in DMSO and water will remain clear and colorless for approximately 24 hours at 4°C, before the inhibitors will precipitate out.

Preparation Note

A cocktail solution may be prepared by adding 1 mL of DMSO and 4 mL of deionized water to the 5 mL size or 5 mL of DMSO and 20 mL of deionized water to the 25 mL size. One mL of the cocktail solution is recommended for the inhibition of the protease activity found in 20 mL of cell lysate from 4g of E. coli cells.